Abstract: An apparatus (1) for cleaning industrial plants comprises a robotic arm to a working head of which are associated suction members suitable for sucking powders and working fragments inside a working volume in which a processing industrial plant is installed (L). The working head comprises an extensible manifold for moving the suction mouth (40) away from the end of the robotic arm thus allowing to reach remote positions and moreover the robotic arm (10) is mounted on moving members, for example a portal, which allow the robotic arm to be moved at different useful working volumes so that an accurate cleaning can be performed on a very large overall volume.