Disclosed is a plasma processing apparatus and a plasma processing method, by which ions of plasma can be injected uniformly over the whole surface of a substrate to be processed, in a short time. Specifically, when the substrate is processed in a reaction container, the gas pressure inside the reaction container is increased. Alternatively, the distance between a plasma processing portion and the substrate is enlarged, or the substrate is temporally moved outwardly of the reaction container. As a further alternative, a shutter is disposed between the plasma producing zone and the substrate. With this procedure, incidence of ions of the plasma upon the substrate can be substantially intercepted for a predetermined time period from the start of plasma production.