A positive photosensitive composition comprising (A) a compound which generates an acid upon irradiation with an actinic ray or radiation, and (B-1) a resin having a group which is decomposed by the action of an acid to increase solubility in an alkaline developing solution and containing at least one structure represented by formulae (I), (II) and (III) as described in the specification or (B-2) a resin having at least one monovalent polyalicyclic group represented by formula (Ib) as described in the specification and a group which is decomposed by the action of an acid to increase solubility in an alkaline developing solution. The positive photosensitive composition containing the resin according to the present invention has high transmittance to far ultraviolet light particularly having a wavelength of 220 nm or less and exhibits good dry etching resistance. Further, the positive photosensitive composition exhibits high sensitivity, good resolution and good pattern profile when far ultraviolet light having a wavelength of 250 nm or less, particularly 220 nm or less (especially an ArF excimer laser beam) is employed as an exposure light source, and thus it can be effectively employed for the formation of fine pattern necessary for the production of semiconductor elements.