Abstract: Particles are prevented from clinging to the back of a wafer in the notch alignment of the wafer, and the problems encountered when a plurality of wafers were aligned all at once are solved. Three support poles 105 are erected on a turntable 103. The substrate outer periphery 104b of wafers 104 is supported by the tapered portions of support pins 107 protruding from the support poles 105. The turntable 103 is driven by a single motor 106, and all of the wafers 104 are rotated at once. During rotation, the notches 104a of all the wafers 104 are detected by an optical sensor 116 provided to a sensor pole 117, and the angular position thereof is stored. The wafers 104 are rotated on the basis of the angular position data, and notch alignment is performed successively, starting with the bottom wafer 104.