The present invention provides a pressure-sensitive adhesive which can prevent electrification of a non-electrification-prevented adherend upon peeling, suppresses occurrence of peeling off even with time or via treatment under a high temperature, and is excellent in adhesion reliance, as well as an antistatic pressure-sensitive adhesive sheet, and surface protecting film using this. The pressure-sensitive adhesive composition of the present invention contains an ionic liquid, and a polymer having a glass transition temperature of Tg of 0.degree. C. or lower as a base polymer, as well as an ethylene oxide group-containing compound and/or a surfactant.