To obtain enough photographic performance even for short time exposure and development, and to avoid contamination of a film.

The photosensitive material to be treated by this method contains a hydrazine deriv. and at least one kind of water-soluble polymer selected from polysaccharides or their derivs. in hydrophilic colloid layers. After the photosensitive material is imagewisely exposed, it is treated in 1 to 19 sec developing time and 10 to 54 sec total treating time. And, the photosensitive material is subjected to washing treatment by supplying a washing water containing 200 mg/m2 to 3 g/m2 of at least one kind of developing agent and an oxidizing agent under specified conditions. And, the washing water contains at least one kind of compd. selected from specified compds.