Abstract: A cleaning device for a tomography device, in particular an MRT, has an examination tunnel. The cleaning device has a nozzle assembly for applying a liquid cleaning agent to a tunnel inner surface facing toward the tunnel axis, a mounting device, which is configured to mount the nozzle assembly on a structural unit of the tomography device parallel to the tunnel axis and displaceably along the examination tunnel, and a control unit, which is configured, in the intended cleaning operation, to specify the application of the cleaning agent in dependence on the movement of the nozzle assembly.