An apparatus has been developed which permits high pressure Mo¨ssbauer resonance studies to 300 kbar. It can be operated with either the source or the absorber under pressure. The pressures are established by x‐ray diffraction measurements, and calibration curves are presented for both the supported taper and Bridgman anvils cells. A motion device involving magnets and phosphor bronze springs, with an adjustable mount, is described. Circuits necessary to control the motion, and to distribute the signals from two devices operating in parallel, are outlined.