To solve the problem of a performance enhancing technique proper to microphotofabrication using far ultraviolet light, particularly ArF excimer laser light, to provide a positive photosensitive composition having small density dependence and a wide side lobe margin, and to further provide a positive photosensitive composition improved also with respect to edge roughness and development defects.

The positive photosensitive compositions comprise (A) a compound which generates an aromatic sulfonic acid substituted by at least one fluorine atom and/or a group having at least one fluorine atom upon irradiation with an active ray or radiation and (B) a resin which has a repeating unit having a specified norbornene structure and a (meth)acrylic repeating unit and is decomposed by the action of an acid to increase solubility in an alkali developing solution.