Abstract: The invention concerns a mobile cleaning device suitable for displacing along and cleaning a series of adjacent tilted solar panels aligned in a row and requiring therefor no superstructure fixed to the row of solar panels. The device includes a supporting frame defining a cleaning plane, on which are mounted a cleaning device suitable for cleaning a surface parallel to the cleaning plane, a support device for maintaining the supporting frame substantially parallel to the surface to be cleaned during the displacement of the cleaning device along a row of solar panels; and a guiding device for guiding the displacement of the cleaning device along a row of solar panels. The guiding device includes at least two, preferably at least three, separate guiding wheels, which are aligned along a straight line parallel to the cleaning plane and adjacent to a first edge of the frame.