PURPOSE: To obtain a negative type radiation sensitive resist having high resolution and high dry etching resistance by adding a specified photosensitive aromatic azide compound and a polymer which is photochemically hardened or made insoluble in a solvent by the azide compound.

CONSTITUTION: A photosensitive composition is obtd. by adding the condensation product of equimolar amounts of an aromatic azide compound having an aldehyde group and pyrrole and a polymer which is photochemically hardened or made insoluble in a solvent by the condensation product. For example, the condensation product and the polymer such as polystyrene are dissolved in a solvent such as chlorobenzene, and the resulting photosensitive soln. is applied to a support and dried to form a photosensitive film. This film is exposed to radiation and developed with chlorobenzene. By the development, the unexposed part is dissolved and removed, and a fine pattern can be obtd. Thus, a negative type radiation sensitive resist having high resolution and high dry etching resistance is obtd. The resist is used as a photographic or copying material or a material for printing plates.