A plasma processing method according to the present disclosure includes disposing a substrate on a substrate support, supplying, into a chamber, a processing gas for processing the substrate, generating, in the chamber, a plasma from the processing gas by using a first RF signal and a second RF signal, and applying a bias signal to the substrate support, and generating the plasma includes superimposing the second RF signal on the first RF signal based on a timing when the bias signal is applied to the substrate support.