EXHIBIT 31.2

I, Paul B. Nolan, 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  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/ Paul B. Nolan
                                                 ---------------------------
                                                 Name: Paul B. Nolan
                                                 Title: Chief Financial Officer