Evaporated fuel treating apparatus and method

A canister (1) contains adsorbent temporarily adsorbing a fuel component in an evaporated fuel which is generated within a fuel tank for an internal combustion engine. A drain passage (6) causes the canister (1) to communicate with atmospheric air. A separator (8) arranged in an atmospheric-air-side end portion of the drain passage (8) separates and removes water from air introduced into the separator. The separator (8) communicates with the drain passage (6) above a port (16) opened to the atmospheric air and a bottom drain hole (17).