Apparatus and method for cleaning the inner surface of a pipeline from deposits and for forming a protective coating are disclosed. The apparatus includes a cleaning tool which is caused to move in the interior of the pipeline by a flow of a fluid, the cleaning tool comprising a plurality of guide discs engaging the pipeline surface and mounted along a longitudinal axis of the cleaning tool, an anode positioned inside the cleaning tool, and an impressed current source electrically connected to the anode and the interior of the pipeline, the interior of the pipeline acting as a cathode when current is applied from the current source so that ions flow from the anode, through the fluid, to the interior of the pipeline.