Disclosed are an antistatic agent which does not impair the appearance and the mechanical strength of a molded article and which provides sufficient permanent antistatic properties to the molded article even when added in a small amount, and an antistatic resin composition containing the same. The antistatic agent (Z) includes: a block polymer (A) containing a block of hydrophobic polymer (a) and a block of hydrophilic polymer (b) as constituent units; and an organic fluorine-modified polyolefin (B). The antistatic resin composition is obtained by containing the antistatic agent in a thermoplastic resin (C).