Fuel vapor processing apparatus

A fuel vapor processing apparatus comprising:

• a first canister having a first adsorbent disposed therein, the first absorbent being capable of adsorbing fuel vapor generated in a vehicle fuel tank and allowing desorption of the adsorbed fuel vapor;
• a second canister having a second adsorbent disposed therein, the second adsorbent being capable of adsorbing fuel vapor contained in a breakthrough gas discharged from the first canister and allowing desorption of the adsorbed fuel vapor,
• wherein the second canister comprises a first passage and a second passage arranged parallel to each other, each of the first passage and the second passage having a first end and a second end opposite to the first end, the first end of each of the first passage and the second passage communicating with the first canister and the second end of each of the first passage and the second passage being opened to an atmosphere;
• wherein the first passage is configured as an adsorption passage having the second adsorbent disposed therein, and
• wherein the second passage is configured as an air passage through which air flows;
• an opening and closing device disposed at the second passage or a passage communicating with the second passage, the opening and closing device being configured to close in a regular state and to open during refueling of fuel into the fuel tank;
• and
• wherein the second passage includes an outer side passage portion surrounding at least a part of a circumference of the first passage.