Abstract: An adapter, particularly for detachably connecting an electrical floor-treating device to an operating appliance, includes a first housing having a first longitudinal axis, a first end portion to be connected to the operating appliance and a second end portion. The adapter further includes a second housing having a second longitudinal axis extending substantially transverse to the first axis, a third portion adapted to be mounted on the second end portion for rotation relative thereto and about the first axis. The second housing is adapted to be mounted on the treating device for pivotal movement relative thereto about the second axis and for rotational movement with the treating device about the first axis.