Microstrip detectors are an exciting new development in proportional counter design in which the usual discrete anode and cathode wires are replaced by conducting strips on an insulating or partially insulating substrate. The devices are fabricated using integrated circuit-type photolithographic techniques and hence offer very high spatial accuracy and uniformity together with the capability of producing extremely fine electrode structures. First introduced by Oed, microstrip proportional counters have now been variously reported having 30 im spatial resolution, rate capacities to iO' mm2 s, and an energy resolution ofbetter than 11% FWHM at5.9 keV. They have been fabricated with anode bars down to 2 tm and on a variety of substrate materials including thin films which can be molded to different shapes. This review will examine the development ofthe microstrip detector with emphasis on the qualities which make this detector particularly interesting for use in astronomy.