A positive photosensitive composition comprises: (A) a resin that has an acid decomposable repeating unit represented by formula (I) and increases its solubility in an alkali developer by action of an acid; (B) a compound that generates an acid in irradiation with actinic light or radiation; (C) a resin that has: at least one of a fluorine atom and a silicon atom; and a group selected from the group consisting of groups (x) to (z); and (D) a solvent: (x) an alkali soluble group, (y) a group which decomposes by action of an alkali developer and increases a solubility of the resin (C) in an alkali developer, and (z) a group which decomposes by action of an acid, ##STR00001## wherein, Xa.sub.1 represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom, Ry.sub.1 to Ry.sub.3 each independently represents an alkyl group or a cycloalkyl group, and at least two of Ry.sub.1 to Ry.sub.3 may be coupled to form a ring structure, and Z represents a divalent linking group.