A device for cleaning heat exchanger pipe bundles. The device includes a guide column supported by a support construction for displacement parallel to itself, wherein the guide column defines a guide path for a slide piece guided slidably along the column, a number of lances connected to the slide piece parallel to the guide column, a hose connected to the slide piece for supplying liquid under high pressure to the lances, and an endless flexible member engaging on the slide piece for reciprocally moving the slide piece along the guide column. The column and the flexible member are assembled from a number of parts so that they can have a length adapted to the conditions.