The present invention relates to a measuring steady rest which has a device for supporting central workpiece regions, in particular, bearing points on shaft parts, in particular crankshafts, and a measurement device integrated therein for directly adjusting the measurement of the workpiece regions before and/or during machining of the shaft parts. The measuring steady rest is preferably designed in the form of a prism, the measurement device being arranged on the bottom of the prism between the lateral flanks of the prism. The present invention further relates to a grinding machine comprising such a measuring steady rest, and to a method for supporting and measuring central workpiece regions on such a grinding machine comprising such a measuring steady rest.