When ship is anchored a long period of time, a lot of marine life adhere to the hull.it is one of cause to be increased fuel cost, so that ship hull need regular cleaning. In general, the cleaning of ship hull is carried out on the ship inspection in dockyard or by divers in harbor. But these are high cost, and have a high risk of accident. One of the solutions to the problem is to use underwater robot in cleaning of ship hull. In this paper, we consider the attitude control method of underwater robot. In addition, we report on cleaning experiment.