An etching method of selectively etching a first region formed of silicon oxide with respect to a second region formed of silicon nitride includes: a process (a) and a process (b). In the process (a), a target object is exposed to plasma of a fluorocarbon gas and a thickness of a protective film on the second region is larger than a thickness of a protective film formed on the first region. In the process (b), the first region is etched by plasma of a fluorocarbon gas. In the process (a), a temperature of the target object is set to 60° C. or more to 250° C. or less.