A plasma processing apparatus includes: a base that has an electrode body provided with a placing surface on which a substrate is placed and a pedestal which supports the electrode body; a lid that is liftable and lowerable with respect to the base and forms a sealed space for performing plasma processing on the substrate placed on the placing surface by being lowered to come into close contact with the pedestal; a cover that is provided integrally with the lid and covers at least a part of an outer edge of the substrate placed on the placing surface when the sealed space is formed; and a guide that is disposed around the electrode body.