To provide a positive type photoresist composition having sufficiently high sensitivity and resolving power in the formation of a contact hole pattern in the production of a semiconductor device, less liable to produce particles in a resist solution and excellent in dependency on density.

The positive type photoresist composition contains (A) an acid generating sulfonium salt compound represented by a specified structure, (B) an acid decomposable resin containing at least specified silicon-containing repeating units or repeating units with a specified structure and having solubility to an alkali developing solution increased by the action of the acid, (C) a solvent, (D) an organic basic compound and (E) a surfactant with a specified structure.