A device is described forinsitu, rotary pin‐on‐disk wear studies in a commercial scanning Auger microscope. This device is mounted on a single 8‐in. vacuum flange and can be installed in place of the normal sample mounting manipulator. The device allows simultaneous measurement of contact resistance and friction coefficient under controlled atmospheric conditions as wear progresses. The surface composition and topography of the wear track are measured without exposure of the surface to contaminating environments or removal of the pin from the wear track. Modifications made to the vacuum system to facilitate atmospheric control are also described.