A conventional substrate processing apparatus for generating plasma cannot generate plasma with high density and thus throughput of substrate processing is low. In order to solve this problem, provided is a substrate processing apparatus including a reaction vessel having a tubular shape and provided with a coil installed at an outer circumference thereof; a cover installed at a first end of the reaction vessel; a gas introduction port installed at the cover; a first plate installed between the gas introduction port and an upper end of the coil; a second plate installed between the first plate and the upper end of the coil; a substrate processing chamber installed at a second end of the reaction vessel; and a gas exhaust part connected to the substrate processing chamber.