A substrate processing apparatus includes a holder for holding a substrate horizontally, a rotator for rotating the holder, a liquid supplier for supplying liquid to the substrate, and a controller for controlling the holder, the rotator, and the liquid supplier. The holder includes a turntable configured to be rotated by the rotator, at least one first clamper configured to be rotated together with the turntable and moved between a clamping position and a releasing position, and at least one second clamper configured to be rotated with the turntable and moved between the clamping and releasing positions independently of the at least one first clamper. The controller controls the at least one first clamper and the at least one second clamper to alternately clamp the peripheral edge of the substrate while the holder is being rotated by the rotator and the liquid is being supplied to the substrate.