Abstract: A holder for positioning silicon wafers on a microscope stage for uniform and repeatable viewing under the microscope. The holder comprises a circumferential rib having an arc of from about 60.degree.-180.degree. diametrically opposed to a radially aligned slit within which a bracket member is positioned. Actuation of the bracket member pushes against a major flat on the silicon wafer, causing the leading edge of the wafer to bear against the abutment. The holder, or platen, is provided with calibration standards on a circumferential edge portion, and is also provided with at least one access port permitting access to the underside of the wafer with vacuum wands.