To provide a positive resist composition in which falling of patterns, a tailing and a scumming are decreased and to provide a positive resist composition in which development defects are decreased.

The positive resist composition contains (A) a resin which contains a repeating unit having an acid decomposable group having an alicyclic structure, a repeating unit having an alicyclic lactone structure and a repeating unit having a hydroxyl group or a cyano group and which increases the solubility rate with an alkali developing liquid by the effect of an acid and (B) a compound which generates an acid by irradiation of active rays or radiation.