EXHIBIT 31.1
I, John D. Heaton, certify that:
1. I have reviewed this annual report on Form 10-K of Nanometrics
Incorporated;
2. Based on my knowledge, this annual report does not contain any
untrue statement of a material fact or omit to state a
material fact necessary to make the statements made, in light
of the circumstances under which such statements were made,
not misleading with respect to the period covered by this
annual report;
3. Based on my knowledge, the financial statements, and other
financial information included in this annual report, fairly
present in all material respects the financial condition,
results of operations and cash flows of the registrant as of,
and for, the periods presented in this annual report;
4. The registrant's other certifying officer and I are
responsible for establishing and maintaining disclosure
controls and procedures (as defined in Exchange Act Rules
13a-15(e) and 15d-15(e)) for the registrant and have:
(a) Designed such disclosure controls and procedures, or
caused such disclosure controls and procedures to be
designed under our supervision, to ensure that
material information relating to the registrant,
including its consolidated subsidiaries, is made
known to us by others within those entities,
particularly during the period in which this annual
report is being prepared;
(b) Evaluated the effectiveness of the registrant's
disclosure controls and procedures and presented in
this report our conclusions about the effectiveness
of the disclosure controls and procedures, as of the
end of the period covered by this annual report based
on such evaluation; and
(c) Disclosed in this annual report any change in the
registrant's internal control over financial
reporting that occurred during the registrant's most
recent fiscal quarter (the registrant's fourth fiscal
quarter in the case of this annual report) that has
materially affected, or is reasonably likely to
materially affect, the registrant's internal control
over financial reporting; and
5. The registrant's other certifying officer and I have
disclosed, based on our most recent evaluation of internal
control over financial reporting, to the registrant's auditors
and the audit committee of registrant's board of directors (or
persons performing the equivalent functions):
(a) All significant deficiencies and material weaknesses
in the design or operation of internal control over
financial reporting which are reasonably likely to
adversely affect the registrant's ability to record,
process, summarize and report financial information;
and
(b) Any fraud, whether or not material, that involves
management or other employees who have a significant
role in the registrant's internal control over
financial reporting.
Date: March 31, 2004 By: /s/ John D. Heaton
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Name: John D. Heaton
Title: Chief Executive Officer