An etching method includes: (a) providing a substrate having an etching target film and a mask on the etching target film to a substrate support in a plasma processing apparatus including a chamber, the substrate support, a plasma generator supplied with source power, and a bias electrode supplied with bias power; and (b) forming a recess by etching the etching target film. In (b), the source power and the bias power are periodically supplied in a cycle that includes a first period and a second period. In the first period, the etching target film is etched, and in the second period, the second processing gas is adsorbed onto the etching target film.