A bagless canister vacuum cleaner includes a selectively removable dirt cup, and an airstream flows rotationally through the dirt cup between an interior wall of the dirt cup and a filter assembly selectively mounted in the dirt cup so that entrained contaminants are separated from the airstream flowing through the dirt cup and collected by the dirt cup. The filter lies substantially parallel to the support surface on which the vacuum cleaner is supported. A cover member is connected to the main housing, and the cover member is selectively movable to and held in an operative position in covering relation with an open first end of a dirt cup. The main housing defines a base conformed to self-support the main housing on a support surface with the dirt cup arranged with its open first end at a higher elevation than its closed second end. The removable dirt cup includes a handle adapted for being held by a user, and the dirt cup defines or includes a spout to facilitate emptying dirt therefrom.