A high‐resolution scanning phase‐measuring acoustic microscope (SPAM) has been developed and used to image the near‐surface residual stress field around features etched in sputtered alumina via the acoustoelastic effect. This microscope operates at 670 MHz and has a resolution of 5–10 &mgr;m, depending upon the amount of defocus. Relative velocity changes of sample surface waves as small as 50 ppm are resolved. Images of the stress field at the tip of a 400‐&mgr;m‐wide slot etched in alumina are presented and compared with a finite element simulation. The SPAM uses an unconventional acoustic lens with an anisotropic illumination pattern which can measure anisotropic effects and map residual stress fields with several &mgr;m resolution and a stress sensitivity of 1/3 MPa in an alumina film.