1
                                                                    EXHIBIT 5(b)




                    [RICHARDS, LAYTON & FINGER LETTERHEAD]








                                December 1, 1997






CMS Energy X-TRAS Pass-Through Trust I
c/o CMS Energy Corporation
Fairlane Plaza South, Suite 1100
330 Town Center Drive
Dearborn, Michigan  48126

                  Re:      CMS Energy X-TRAS Pass-Through Trust I

Ladies and Gentlemen:

                  We have acted as special Delaware counsel for CMS Energy
Corporation, a Michigan corporation (the "Company"), and CMS Energy X-TRAS
Pass-Through Trust I, a Delaware business trust (the "Trust"), in connection
with the matters set forth herein. At your request, this opinion is being
furnished to you.

                  For purposes of giving the opinions hereinafter set forth, our
examination of documents has been limited to the examination of originals or
copies of the following:

                  (a) The Certificate of Trust of the Trust (the "Certificate of
Trust") as filed in the office of the Secretary of State of the State of
Delaware (the "Secretary of State") on November 21, 1997;

                  (b) The Declaration of Trust of the Trust, dated as of
November 21, 1997, among the Company, as Sponsor, and the trustees of the Trust
named therein;

                  (c) The Registration Statement (the "Registration Statement")
on Form S-3, including a preliminary prospectus and preliminary prospectus
supplement (the "Prospectus") relating to the Pass-Through Certificates of the
Trust representing preferred undivided beneficial interests in the assets of the
Trust (each, a "Pass-Through Certificate" and collectively, the



   2
CMS Energy X-TRAS Pass-Through Trust I
December 1, 1997
Page 2


"Pass-Through Certificates"), as proposed to be filed by the Company, the
Trust and others as set forth therein with the Securities and Exchange
Commission on or about December 1, 1997;

                  (d) A form of Amended and Restated Declaration of Trust of the
Trust, to be entered into among the Company, as Sponsor, the trustees of the
Trust named therein, and the holders, from time to time, of undivided beneficial
interests in the assets of the Trust (including Annex A and Exhibits A-1 and A-2
thereto) (the "Declaration"), attached as an exhibit to the Registration
Statement; and

                  (e) A Certificate of Good Standing for the Trust, dated
December 1, 1997, obtained from the Secretary of State.

                  Initially capitalized terms used herein and not otherwise
defined are used as defined in the Declaration.

                  For purposes of this opinion, we have not reviewed any
documents other than the documents listed in paragraphs (a) through (e) above.
In particular, we have not reviewed any document (other than the documents
listed in paragraphs (a) through (e) above) that is referred to in or
incorporated by reference into the documents reviewed by us. We have assumed
that there exists no provision in any document that we have not reviewed that is
inconsistent with the opinions stated herein. We have conducted no independent
factual investigation of our own but rather have relied solely upon the
foregoing documents, the statements and information set forth therein and the
additional matters recited or assumed herein, all of which we have assumed to be
true, complete and accurate in all material respects.

                  With respect to all documents examined by us, we have assumed
(i) the authenticity of all documents submitted to us as authentic originals,
(ii) the conformity with the originals of all documents submitted to us as
copies or forms, and (iii) the genuineness of all signatures.

                  For purposes of this opinion, we have assumed (i) that the
Declaration and the Certificate of Trust are in full force and effect and have
not been amended, (ii) except to the extent provided in paragraph 1 below, the
due creation or due organization or due formation, as the case may be, and valid
existence in good standing of each party to the documents examined by us under
the laws of the jurisdiction governing its creation, organization or formation,
(iii) the legal capacity of natural persons who are parties to the documents
examined by us, (iv) that each of the parties to the documents examined by us
has the power and authority to execute and deliver, and to perform its
obligations under, such documents, (v) the due authorization, execution and
delivery by all parties thereto of all documents examined by us, (vi) the
receipt by each Person to whom a Pass-Through Certificate is to be issued by the
Trust (collectively, the "Pass-Through Certificate Holders") of a Pass-Through
Certificate for such



   3


CMS Energy X-TRAS Pass-Through Trust I
December 1, 1997
Page 3

Pass-Through Certificate and the payment for the Pass-Through Certificate
acquired by it, in accordance with the Declaration and the Registration
Statement, and (vii) that the Pass-Through Certificates are issued and sold to
the Pass-Through Certificate Holders in accordance with the Declaration and the
Registration Statement. We have not participated in the preparation of the
Registration Statement and assume no responsibility for its contents.

                  This opinion is limited to the laws of the State of Delaware
(excluding the securities laws of the State of Delaware), and we have not
considered and express no opinion on the laws of any other jurisdiction,
including federal laws and rules and regulations relating thereto. Our opinions
are rendered only with respect to Delaware laws and rules, regulations and
orders thereunder which are currently in effect.

                  Based upon the foregoing, and upon our examination of such
questions of law and statutes of the State of Delaware as we have considered
necessary or appropriate, and subject to the assumptions, qualifications,
limitations and exceptions set forth herein, we are of the opinion that:

                  1. The Trust has been duly created and is validly existing in
good standing as a business trust under the Delaware Business Trust Act.

                  2. The Pass-Through Certificates will represent valid and,
subject to the qualifications set forth in paragraph 3 below, fully paid and
nonassessable undivided beneficial interests in the assets of the Trust.

                  3. The Pass-Through Certificate Holders, as beneficial owners
of the Trust, will be entitled to the same limitation of personal liability
extended to stockholders of private corporations for profit organized under the
General Corporation Law of the State of Delaware. We note that the Pass-Through
Certificate Holders may be obligated to make payments as set forth in the
Declaration.

                  We consent to the filing of this opinion with the Securities
and Exchange Commission as an exhibit to the Registration Statement. In
addition, we hereby consent to the use of our name under the heading "Validity
of the Certificates" in the Prospectus. In giving the foregoing consents, we do
not thereby admit that we come within the category of Persons whose consent is
required under Section 7 of the Securities Act of 1933, as amended, or the rules
and regulations of the Securities and Exchange Commission thereunder. Except as
stated above, without our prior written consent, this opinion may not be
furnished or quoted to, or relied upon by, any other Person for any purpose.

                                            Very truly yours,


                                            /s/ Richards, Layton & Finger