Scatter plate interferometers provide a precise method to test the quality of concave mirrors. In this article we describe a method to integrate a scatter plate and a projection lens into a single binary micro-optical element, which is a crucial part of the scatter plate interferometer. We have designed an integrated element with the aid of a computer and fabricated it using thee-beam lithography method. We present experimental verification and some computer simulation results. ©1998 American Institute of Physics.