Disclosed is a substrate processing apparatus which can inhibit the occurrence of spots, such as watermarks, by reducing the remaining of the liquid that has been used for liquid treatment, inhibit the turn-over of the wafer, and improve throughput. In the disclosed substrate processing apparatus including a carrying means for carrying a semiconductor wafer W while vertically holding the wafer, a wafer boat (a carrying means) includes lower holders holding the bottom portion of the wafer, and a couple of left/right upper holders for holding the bottom outer edges of the wafer when the wafer is turned over. The lower holder includes a holding groove part and a turn-over prevention groove part, which are integrally formed with each other. The holding groove part includes holding grooves directly holding the bottom portion of the wafer, and the turn-over prevention groove part is disposed adjacent to the holding groove part and includes turn-over prevention grooves for holding the wafer when the holding of the wafer by the holding grooves has been released.