A vacuum cleaner is disclosed, which includes a main body formed of a fan motor generating a driving force therein, a fan, and a cyclone dust collector, a suction head connected to the main body and sucking in all kinds of impurity existing on a surface that is to be cleaned, a suction hose connected to the front portion of the main body and an extension tube connected to the suction head both installed between the main body and the suction head, a dust collecting chamber detachably fixed on a rear side of the main body and having a handle on an outer rear surface thereof, a lower holding part of the handle on the dust collecting chamber projecting beyond the lower circumference of the wheels and coming into contact with the surface of a lower step, when the front portion of the main body of the vacuum cleaner is fastened to the edge of an upper step, and a roller caster formed on both sides of the lower front portion of the main body allowing back-and-forth motions and rotations on a flat surface and fastening the vacuum cleaner to the edge of the upper steps, thereby preventing the main body of the vacuum cleaner from slipping down the stairway.