Patent ID: 7341048

Claim:
A fuel vapor treatment apparatus treating a fuel vapor evaporated in a fuel tank, the fuel vapor treatment apparatus comprising: a canister accommodating an adsorbent adsorbing the fuel vapor, the canister including a tank port communicating with the fuel tank through a tank passage; a purge passage connecting a purge port of the canister with an intake pipe of an internal combustion engine, the purge passage introducing an air including the fuel vapor described from the adsorbent into the intake pipe; a concentration-detecting unit detecting a concentration of the fuel vapor contained in an air flowing in the purge passage; an atmosphere passage communicating with an atmosphere port of the canister, through which an air flows into the canister and discharges from the canister; and a concentration-detecting passage connecting the purge passage with the canister through the concentration-detecting unit, wherein the concentration-detecting passage introduces the air including the fuel vapor into an intermediate portion of a space accommodating the adsorbent, the air including the fuel vapor is introduced to the concentration-detecting unit from the purge passage, and the atmosphere port and the purge port are connected to the space at both end portions thereof.