A disc holding apparatus including a plurality of movable holding claws, which have a holding section abutting to the outer circumference of a wafer having a notch and are arranged in the circumference direction of the wafer. The wafer is held by having each holding section on the inner edge side of each movable holding claw abut to the outer circumference of the wafer, thereby, at the time of detecting the notch by a sensor including a light source and a light receiving section, even when one of the holding sections abuts to the outer circumference of the wafer at a part where the notch exists, light from the light source is permitted to enter the light receiving section through the notch without being blocked by the holding section. Even when the wafer is held at the part where the notch exists, the wafer is not required to be correctly held again and throughput is improved with a shortened process time.