A technique to acquire a photoresist composition which can reduce occurrence of defects of a resist pattern after development is provided. Further, a technique to obtain a photoresist composition having excellent storage stability characteristics as a resist solution (storage stability); and a technique to obtain a photoresist composition which reduces the change of sensitivity and resist pattern size after treatment almost completely are provided. A photoresist composition containing a resin component (A), an acid-generating component (B) for generating an acid under exposure, and an organic solvent (C) is passed through a first filter 2a equipped with a first membrane having zeta potential of more than −20 mV but no more than 15 mV in distilled water of pH 7.0.