Provided is a prober capable of suppressing the increase in installation area and the increase in device cost, and also improving the throughput, while maintaining the accuracy of the moving position of an alignment device shared by each of measuring units. The prober includes: a plurality of measuring units, each of which has a probe card electrically connected to a test head; a wafer chuck that holds a wafer in which a plurality of chips are formed; an alignment device which performs relative alignment between the probe card and the wafer held by the wafer chuck; a moving device which moves the alignment device among the measuring units; and a positioning and fixing device which is provided for every of the measuring units, and positions and fixes the alignment device which is moved to each of the measuring units.