Patent ID: 7008471

Claim:
A filter, for a canister that is connected to a fuel tank to adsorb fuel vapor vaporized in the fuel tank and includes a canister housing and a canister main body, which is received in the canister housing and communicates with the fuel tank at one end, wherein the canister housing includes an atmospheric port and an atmospheric air passage, and the atmospheric air passage receives the filter and communicates between the other end of the canister main body and the atmospheric port, which in turn communicates with the atmosphere, the filter comprising: an active carbon layer that includes an active carbon material, which adsorbs fuel vapor vaporized in the fuel tank; and first and second holding layers that sandwich the active carbon layer therebetween in a flow direction of air, which passes through the active carbon layer, wherein: the first holding layer is positioned on an atmosphere side of the active carbon layer; the second holding layer is positioned on a fuel tank side of the active carbon layer; at least the first holding layer, of the first and the second holding layers, is made of an unwoven fabric material that filters foreign particles contained in atmospheric air conducted in the atmospheric air passage; and a thickness of the first holding layer measured in the flow direction is greater than a thickness of the second holding layer measured in the flow direction.