A substrate processing apparatus includes a rotary table comprising a base plate having a front surface where at least one suction hole is provided and an attraction plate having a front surface contacted with a non-processing surface of a substrate to attract the substrate, a rear surface contacted with the front surface of the base plate, and at least one through hole through which the front surface and the rear surface are connected; a rotation driving device configured to rotate the rotary table around a rotation axis; and a suction device configured to act a suction force on the suction hole, to contact the base plate with the attraction plate by acting the suction force between the base plate and the attraction plate, and to firmly contact the attraction plate with the substrate by acting the suction force between the attraction plate and the substrate through the through hole.