Fuel cap and vaporized fuel adsorption canister used in the fuel cap

A fuel cap comprising:

• an outer cap as an outer envelope;
• an inner cap removably fitted in the outer cap through an opening of the outer cap;
• and
• a canister located in a space between the outer cap and the inner cap for adsorbing a vaporized fuel,
• the fuel cap closing a fuel filler port for feeding a fuel to a fuel tank, the canister adsorbing a vaporized fuel vaporized from the fuel in the fuel tank,
• at least one of the outer cap and the inner cap defining a communication hole communicating with the space and an exterior,
• the canister including a housing;
• and an adsorbent accommodated in the housing,
• the housing defining, on an end surface directed to the inner cap, an inlet for a vaporized fuel to flow into the inlet,
• the housing defining, on another end surface directed to an inner surface of the outer cap, an outlet for a gas, from which the vaporized fuel has been absorbed, to flow out of the outlet,
• said another end surface of the housing contacting said inner surface of the outer cap,
• said inner surface of the outer cap and said another end surface of the housing having a clearance securement member as a spacer interposed therebetween and located proximate to the outlet, the clearance securement member securing a clearance between said inner surface of the outer cap and said another end surface of the housing, said clearance connecting the outlet and the communication hole each other.