A substrate processing apparatus capable of removing deposits attached on a component of a lower temperature in a gap between two components, temperatures of which are greatly different from each other, without degrading a working ratio of the substrate processing apparatus. In the substrate processing apparatus, a chamber receives a wafer, a focus ring surrounds the wafer disposed in the chamber, a side surface protective member transmits a laser beam, a laser beam irradiating apparatus irradiates the laser beam to the side surface protective member, an inner focus ring of the focus ring is disposed adjacent to the wafer and is cooled down and an outer focus ring surrounds the inner focus ring and is not cooled down in a focus ring, and a facing surface of the side surface protective member faces a gap between the inner focus ring and the outer focus ring.