Disclosed is a plasma etching method including a deposition process and an etching process. For a processing target object including a base layer and a photoresist having a predetermined pattern which are laminated in sequence, the deposition process deposits a protective layer including silicon and carbon on the photoresist of the processing target object by plasma of a first processing gas including silicon tetrachloride gas, methane gas, and hydrogen gas. The etching process etches the base layer by plasma of a second processing gas using the photoresist including the protective layer deposited thereon, as a mask. The second processing gas is different from the first processing gas.