A fuel tank has a tank body and a fuel inlet projecting upwardly from the tank body. The fuel tank includes a cylindrical member extending into the tank body, a canister, and a discharging passage in communication with the canister housing an adsorbent for absorbing fuel vapor from the fuel tank. A space between an outer circumferential surface of the cylindrical member and an inner circumferential surface of the fuel inlet is hermetically sealed by a seal. The cylindrical member has a passage for communicating an inside of the cylindrical member with a portion of an outside of the cylindrical member that is lower than the hermetically sealed space. The passage allows air in the tank body to enter the fuel inlet when fuel overflows from the fuel inlet, thereby inhibiting flow of fuel into the canister through the discharging passage.