PURPOSE: To evade pollution due to the volatilization of a solvent, by easily crosslinking a coating film formed in a dry method, by using γ-rays as an energy source for crosslinking.

CONSTITUTION: A solvent-soluble high molecular substance is coated on a base material in a dry coating method to form a coating film. This coating film, mounting a screen in a prescribed pattern with γ-rays shielding effect, is irradiated with γ-rays via the screen. As a result, the coating film irradiated with γ-rays is not crosslinked where γ-rays are shielded from by the screen and crosslinked where γ- rays are allowed by the screen to penetrate. When this is dipped in a solvent that dissolves the part which is not crosslinked, the coating film is elutriated only where the crosslinking is not carried out to expose the base material and the crosslinked part stays in a shape that corresponds to the pattern of the screen. Therefore, an integrated circuit in a pattern that corresponds to that of the screen can be formed.