SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

The substrate processing apparatus according to the present invention comprises: a processing container including a processing chamber therein which can be decompressed to a pressure lower than atmospheric pressure; a holding part for holding the substrate in the processing chamber; and a nozzle that sprays a gas to irradiate the gas cluster on the first main surface of the substrate held by the holding unit. The processing container includes: a facing wall including a first facing surface facing the first main surface of the substrate; a plate provided on a portion of the first facing surface of the facing wall; and a through hole penetrating the opposing wall and the plate. The plate has a second facing surface facing the first main surface of the substrate. The through hole is a passage for the gas and has an outlet in the second opposing surface of the plate. A first gap is formed between the facing wall and the substrate, a second gap is formed between the plate and the substrate, and the second gap is n