A diffraction grating mounted in the focal region of a modified scanning electron microscope has been used to produce far-infrared Smith–Purcell radiation. The electron beam radius, voltage, and current ranges were 3–27 &mgr;m, 27–40 kV, and 10–140 &mgr;A, respectively. The micron scale of the electron beam was well matched to the evanescent surface waves of the grating. The measured wavelength range extended from 288 to 803 &mgr;m, and both the wavelengths and the intensities observed were in accord with expectations based on theory. The details of the experiment and a summary of the results will be discussed. ©1997 American Institute of Physics.