To treat evaporated fuel in a canister without depending on drive of an internal combustion engine.
This system includes first liquid chamber 801 connected to a fuel supply device 205 for supplying fuel to the internal combustion engine 200 and reserving fuel FL1, a second liquid chamber 816 reserving fuel FL2, a transfer means 821 transferring fuel reserved in the first liquid chamber 801 and the second liquid chamber 816 from one to another, a canister 811 reserving evaporated fuel caused by fuel FL1, a seal valve 809 opening and sealing a part between the first liquid chamber 801 and a canister 811, a calculation means 100 calculating quantity of evaporated fuel reserved in the canister, and a control means 100 controlling each part. The control means 100 transfers fuel FL1 from the first liquid chamber 801 to the second liquid chamber 816 and opens the seal valve if the quantity of evaporated fuel reserved in the canister 811 is not less than prescribed quantity.
Koji Yamamoto
Satoshi Nakamura