CANISTER

A canister includes two or more chambers in which an adsorbent configured to adsorb an evaporated fuel is placed, a case, an inflow port, an atmosphere port, and outflow port. The case forms a main chamber that is one of the two or more chambers. The inflow port and the outflow port are provided to a first end of the main chamber. The case includes at least one reduced part that is a wall-like part forming an area in the main chamber in the vicinity of the first end. In the at least one reduced part, an area of a cross-section of the main chamber orthogonal to flow directions of a fluid is reduced towards the first end.