Patent ID: 7363803

Claim:
A canister included in a fuel vapor processing apparatus for processing fuel vapor generated in a fuel tank and incorporating, in a casing, an adsorbent for adsorbing the fuel vapor, wherein the canister comprises a diagnosing function part for the fuel vapor processing apparatus, the diagnosing function part being integrally mounted nearly centrally of the casing so that the canister has a center of gravity located nearly centrally of the canister, wherein the diagnosing function part is a pump module for changing the internal pressure of the casing; wherein the casing is in the shape of a generally U-shaped cylindrical body having a first end portion through which the fuel vapor is introduced in and discharged out of the canister and a second end portion which is able to communicate with atmosphere, and the casing includes a valley portion positioned nearly centrally, and the pump module is mounted in the valley portion.