Disclosed is a process for the production of a semiconductor device, which comprises forming a film of a resist composed of a substance generating an acid catalyst by being irradiated with radiation and a polymer having an Si-containing group that can be eliminated by the acid catalyst, irradiating the resist film with radiations and patterning the irradiated resist film by oxygen reactive ion etching, ECR etching or reactive ion beam etching. This process is advantageously used for preparing a semiconductor device by the two-layer resist method.