Level measuring device for humidifier

There is provided a level measuring device for a humidifier, which comprises a liquid container (3) having a bottom plate (11) and a housing (2) having a heating plate (8), for heating the liquid in the liquid container (3) the heating plate (8) can be heated and the bottom plate (11) in contact with the heating plate (8) can be brought, characterized in that the filling level measuring device for capacitively measuring the filling level of the liquid in the liquid container (3) a first electrode (11) and a second electrode (13), each connected to an alternating voltage source (20) are connected, and having a measuring device which is suitable to measure the capacitance between the first electrode (11) and the second electrode (13), wherein the housing (2) a first wall (27 ) which is substantially adjacent to a second wall (15) of the liquid container (3), wherein the bottom plate (11) as the first electrode (11) is provided and the second electrode (13) is such arranged on the first wall (27) that it is the second wall (15) of the liquid container (3) opposite.