To provide a positive type photoresist composition for exposure with far UV having superior sensitivity in the resolution of contact holes in the production of a semiconductor device, capable of preventing the occurrence of particles in the dissolution of solid components in a solvent or during storage with time and capable of also preventing a variation of sensitivity due to storage with time.

The positive type photoresist composition contains a compound which generates an acid when irradiated with active rays or radiation, a resin having a specified structure and a velocity of dissolution in an alkali developing solution increased by the action of the acid and a specified mixed solvent.