A plasma processing apparatus that performs plasma processing on a substrate held on a transport carrier including an annular frame and a holding sheet. The apparatus includes: a process chamber; a plasma excitation device that generates plasma; a stage in the chamber; a cooling mechanism for cooling the stage; a cover that partly covers the holding sheet and the frame and has a window section through which the substrate is partly exposed to plasma; and a movement device that moves a relative position of the cover to the frame. The cover has a roof section, a cylindrical circumferential side section extending from a circumferential edge of the roof section toward the stage, and a correction member that protrudes from the roof section and/or the circumferential side section toward the frame and presses the frame onto the stage to correct warpage of the frame.