PURPOSE: To enable sensitivity to be enhanced, γ value to be lowered, and a halftone image to be reproduced without using a sensitizing layer by exposing an unexposed photosensitive film to a small amt. of actinic ray immediately before imagewise exposure.

CONSTITUTION: A photosensitive film has a photosensitive layer made of a photosensitive material contg. a binder, a polymerizable monomer for serving adhesiveness, an alloxazine, deriv. as a photopolymn. initiator and a tertiary amine between two supports in which at least one of both supports has the light transmittance. Preexposure having intensity insufficient for hardening the photosensitive material is given to the photosensitive layer. It is imagewise exposed, and a pigmen is attached to the layer to form an image. The preexposure amt. is controlled so as the allow the pigment to be used for development not to attach to the layer, and regulated to ≤about 40% of the exposure amt. necessary to expose it without omitting the preexposure.