PROBLEM TO BE SOLVED: To obtain the positive photosensitive composition good in the profiles of a resist pattern and high in sensitivity and resolution and to prevent variation of performance with the lapse of time after exposure by incorporating a specified compound to be allowed to generate sulfonic acid by irradiation with activated rays or the like and a resin having groups each decomposable by action of acid and capable of increasing solubility in an alkaline developing solution. SOLUTION: This photosensitive composition contains the compound to be allowed to generate the sulfonic acid by irradiation with activated rays or radiations represented by formula I and the resin having groups each decomposable by action of acid and capable of increasing solubility in an alkaline developing solution. In formula I, each of R1 -R10 is an H or halogen atom or the like and at least one of them is a group represented by formula II or III; in formulae II and III, R' is an H atom or an alkyl group or the like; R" is an alkyl or aryl or the like; Y is a straight or branched alkylene group or the like; in formula I, X is an n-valent 1-20C straight or branched or cyclic alkylsulfonate ion or the like; and (n) is 1, 2, or 3.