To solve the problem that, although as an antistatic resin composition, there are known hitherto an antistatic resin composition incorporated with a surfactant into a thermoplastic resin and the like, the surfactant is water soluble and therefore deteriorates mechanical characteristics, appearance, and water resistance of a molded product when its amount used is increased in order to enhance the antistatic property, and to provide an antistatic agent which imparts a superior antistatic property to the thermoplastic resin molding without lowering its water resistance and mechanical characteristics.

The antistatic agent comprises an ionic liquid having an initial electrical conductance of 1-200 ms/cm and a block polymer containing 10-90 wt.% of a polyether block structure in the molecule and having a water absorption of 10-150%.