A honeycomb adsorbent having a cylindrical column shape, the honeycomb adsorbent formed by molding and baking powdery activated carbon together with binder and installed in a closest chamber to a drain port of a canister having a plurality of chambers (6,7,8), the honeycomb adsorbent comprising: a plurality of cell passages extending along an axial direction of the honeycomb adsorbent; characterized in that said honeycomb adsorbent further comprises: macropores with a pore diameter equal to or greater than 50 nm and less than 1000 nm formed with fibrous meltable core melting away during the baking, the macropores being configured to have a volume of 0.15 ml/g ~ 0.35 ml/ g as measured by mercury penetration according to ISO 15901-1 with respect to an overall weight of the honeycomb adsorbent; and metal oxide particles having a proportion of weight of 150 ~ 250 % with respect to the activated carbon, and the plurality of cell passages being configured so that a pitch defined by a distance between two center points of adjacent cell passages is within a range of 1.5 mm ~ 1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm ~ 0.60 mm, whereby the honeycomb adsorbent exhibits BWC (Butane Working Capacity) of 6.5 g/dL or greater, measured pursuant to ASTM D5228. a plurality of cell passages extending along an axial direction of the honeycomb adsorbent; characterized in that said honeycomb adsorbent further comprises: macropores with a pore diameter equal to or greater than 50 nm and less than 1000 nm formed with fibrous meltable core melting away during the baking, the macropores being configured to have a volume of 0.15 ml/g ~ 0.35 ml/ g as measured by mercury penetration according to ISO 15901-1 with respect to an overall weight of the honeycomb adsorbent; and metal oxide particles having a proportion of weight of 150 ~ 250 % with respect to the activated carbon, and the plurality of cell passages being configured so that a pitch defined by a distance between two center points of adjacent cell passages is within a range of 1.5 mm ~ 1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm ~ 0.60 mm, whereby the honeycomb adsorbent exhibits BWC (Butane Working Capacity) of 6.5 g/dL or greater, measured pursuant to ASTM D5228. macropores with a pore diameter equal to or greater than 50 nm and less than 1000 nm formed with fibrous meltable core melting away during the baking, the macropores being configured to have a volume of 0.15 ml/g ~ 0.35 ml/ g as measured by mercury penetration according to ISO 15901-1 with respect to an overall weight of the honeycomb adsorbent; and metal oxide particles having a proportion of weight of 150 ~ 250 % with respect to the activated carbon, and the plurality of cell passages being configured so that a pitch defined by a distance between two center points of adjacent cell passages is within a range of 1.5 mm ~ 1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm ~ 0.60 mm, whereby the honeycomb adsorbent exhibits BWC (Butane Working Capacity) of 6.5 g/dL or greater, measured pursuant to ASTM D5228.