A substrate processing apparatus, for generating a plasma from a gas by a high frequency energy and etching a substrate in a processing chamber by radicals in the plasma, includes a high frequency power supply configured to supply the high frequency energy into the processing chamber, a gas supply source configured to introduce the gas into the processing chamber, a mounting table configured to mount the substrate thereon, and a partition plate provided in the processing chamber and configured to divide an inner space of the processing chamber into a plasma generation space and a substrate processing space and suppress passage of ions therethrough. The partition plate and a portion of an inner wall surface of the processing chamber which is positioned at least above the mounting table are covered by a dielectric material having a recombination coefficient of 0.002 or less.