Abstract: A vacuum cleaner for reservoirs, especially swimming pools, including a working chamber provided with an inlet for liquid, connected with a vacuum generating unit. Between the inlet of liquid and the vacuum generating unit a rotary-shaped rolling rotor is placed in the flow of drawn in liquid. The rolling rotor is arranged in a swivelling and rotary manner and encompassed with a surface for rolling. In the contact point between the rolling rotor and the surface for rolling the rolling rotor has a smaller diameter than the surface for rolling. The rotor is connected with at least one brush.