Hot cleaning apparatus for surfaces, adapted to ensure an adequate wetting of the cleaning cloth in an automatic manner, which cleaning apparatus is substantially constituted by a first upper part and a second lower part joined to each other in a hinged way through a movable connection, as for example an universal joint or the like, wherein the first upper part comprises a support body to which an upper handle with grip and a power supply cable are joined, and therein there are inserted an electronic circuit board, connected to and supplied by the cable, a tank for the water lower joined with a first flexible or stiff pipe to an electric pump, such a support body being provided on its surface with control and command means for the cleaning modality, and said second lower part comprising a means support body, shaped like a casing and preferably made of plastic, adapted to contain lower in succession at least a heating means, at least a cleaning cloth, joined with their upper part to said electric pump with a second stiff or flexible pipe in such a way that the water may be taken from the tank by the electric pump for being then conveyed toward such a cleaning cloth, at least an absorbing multilayer element being inserted into and secured in contact between said heating means and said cleaning cloth, wherein said absorbing multilayer element is constituted by a quadrangular peripheral hollowed frame (24, 40), wherein a quadrangular body (35, 44) is inserted, which is in turn constituted by at least a central panel (19, 45), made of absorbing material, to which there being coupled on to the upper (36, 46) and lower (37, 47) surfaces thereof a layer made of polyester material (20, 48), which resists to temperatures up to 140°C, as for example nonwoven fabric, characterized in that one or more sensors for detecting the moisture (22, 43), made of conductive material, are installed lower to said multilayer element, in an insulated way from this latter, which sensors are arranged in to contact with the underlying cleaning cloth, such a central panel (19, 45) being adapted to receive, to absorb and to keep a certain quantity of water, that is supplied by the electric pump through the second pipe, acting so ad additional water tank, for let the water get gradually toward the cleaning cloth applied under it, said moisture sensors (22, 43) being adapted to detect the electrical conductivity of the water present into the cleaning cloth only, and the electronic circuit board being adapted to read the value of the electrical resistivity between two sensor (22, 43) made of conductivity material and to compare it with a reference value preset thanks to the control and command means for the cleaning modality, in a manner that if the cleaning cloth is too dry, the resistivity value is very high (R>X), the electronic circuit board inserts the electric pump that takes the water from the tank and supplied it to the panel (19, 45), which absorbs and releases it to the cleaning cloth, dunking this latter, thereby increasing the electrical conductivity and by decreasing the resistivity, said electric pump remaining active up to the electrical resistivity value detected between the sensors (22, 43) is equal to or lower than the reference value of the electronic circuit board (R=X), and being adapted to turn of itself automatically when into the cloth there is present the suitable desired quantity of water/moisture for the cleaning operations, subsequently, during the use of the cleaning apparatus, the quantity of water into the cloth decreases slowly, while consequently the electrical resistivity between the sensors (22, 43) decrease, by returning to the state R>X, thereby let the cycle of activation of the electric pump repeat.