A plasma processing apparatus includes a chamber; a first electrode facing an inside of the chamber; a radio-frequency power supply configured to supply a radio-frequency power to the first electrode; a feeding rod configured to feed the radio-frequency power to a center of a surface of the first electrode opposite to a surface facing the inside of the chamber; a conductive plate provided in parallel to the surface of the first electrode opposite to the surface facing the inside of the chamber, the plate being grounded; and a dielectric plate connecting the first electrode and the conductive plate, and having a shape that is rotationally symmetric with respect to a center of the first electrode.