Exhibit 16.1 June 17, 2004 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Gentlemen: We have read Item 4 of Form 8-K dated June 16, 2004 of Merrimac Industries, Inc. and are in agreement with the statements contained in the second through fifth paragraphs on page 2 therein. We have no basis to agree or disagree with other statements of the registrant contained therein. /s/ Ernst & Young LLP