PURPOSE: To provide a radiation resist excellent in resolution and with high sensitivity by using a mixture of polymer composed of methacrylic acid ethoxyethyl and photocopolymerization starting agent which generates acid with light.

CONSTITUTION: A substrate is coated with a mixture of polymer composed of methacryl acid ethoxyethyl expressed by the general formula, and a photocopolymerization starting agent generating acid with light, and dried to provide a resist film having high transmissive property. After the resist film is irradiated selectively with radiation, it is heated, and developped with alkali developper, thus providing sub-micro patterns with high definition.