A plasma processing method includes etching a removing target film by supplying onto a peripheral portion of a substrate being rotated a first processing liquid containing hydrofluoric acid and nitric acid at a first mixing ratio; and etching the removing target film by, after supplying the first processing liquid onto the substrate, supplying onto the peripheral portion of the substrate being rotated a second processing liquid containing the hydrofluoric acid and the nitric acid at a second mixing ratio in which a content ratio of the hydrofluoric acid is lower and a content ratio of the nitric acid is higher than in the first processing liquid. When removing the removing target film made of SiGe, amorphous silicon or polysilicon from the peripheral portion thereof, an underlying film, for example, a film made of SiO2, which exists under the removing target film, can be appropriately left.