Wet cleaning device for wet cleaning of a floor surface, comprising - a floor part which in an operating state is supported on the floor surface, - at least one floor-treatment tool which is arranged on the floor part and, in the operating state, rests on the floor surface at least partially, - at least one tool drive by means of which drive, in the operating state, the at least one floor-treatment tool is driven and movable on the floor surface, - a hand-guidance part which is provided for manual direction control of the floor part on the floor surface, - a joint arrangement comprising at least two joint axes (E, F) and by means of which the hand-guidance part is connected to the floor part for articulation and torque transmission about its longitudinal axis, - a collection container which is provided for collecting of liquid sucked up from the floor surface and arranged on the hand-guidance part for pivoting together with the hand-guidance part, - a suction drive by means of which drive, in the operating state, air can be drawn off via an air intake opening from the collection container such that the collection container is vacuum pressurized for suction of the liquid, - and a control device which is configured at least for function control of the suction drive and/or the tool drive, - characterized in that a detection device is provided and connected to the control device, which detection device is configured for detecting an inclination angle of the hand-guidance part, wherein the control device is configured such that, as a function of the detected inclination angle, a protective function is controllable to prevent sucking in of liquid from the collection container through the air intake opening due to inclination. - a floor part which in an operating state is supported on the floor surface, - at least one floor-treatment tool which is arranged on the floor part and, in the operating state, rests on the floor surface at least partially, - at least one tool drive by means of which drive, in the operating state, the at least one floor-treatment tool is driven and movable on the floor surface, - a hand-guidance part which is provided for manual direction control of the floor part on the floor surface, - a joint arrangement comprising at least two joint axes (E, F) and by means of which the hand-guidance part is connected to the floor part for articulation and torque transmission about its longitudinal axis, - a collection container which is provided for collecting of liquid sucked up from the floor surface and arranged on the hand-guidance part for pivoting together with the hand-guidance part, - a suction drive by means of which drive, in the operating state, air can be drawn off via an air intake opening from the collection container such that the collection container is vacuum pressurized for suction of the liquid, - and a control device which is configured at least for function control of the suction drive and/or the tool drive, - characterized in that a detection device is provided and connected to the control device, which detection device is configured for detecting an inclination angle of the hand-guidance part, wherein the control device is configured such that, as a function of the detected inclination angle, a protective function is controllable to prevent sucking in of liquid from the collection container through the air intake opening due to inclination.