<PAGE>
As filed pursuant to Rule 424(b)(1)
Under the Securities Act of 1933
Registration No. 333-95115
SUPPLEMENT TO PROSPECTUS DATED MARCH 2, 2000
The table listing the Proceeds to Nanometrics (before expenses) and Proceeds
to the Selling Shareholders (before expenses) was previously incorrectly
stated. That table is amended and restated in its entirety as follows:
<TABLE>
<CAPTION>
Per
Share Total
------ ------------
<S> <C> <C>
Public Offering Price...................................... $38.50 $134,750,000
Underwriting Discount...................................... $ 2.21 $ 7,735,000
Proceeds to Nanometrics (before expenses).................. $36.29 $ 63,507,500
Proceeds to the Selling Shareholders (before expenses)..... $36.29 $ 63,507,500
</TABLE>
The date of this Prospectus Supplement is March 6, 2000
