PURPOSE: To clean the inside of an oven tank effectively by installing a plurality of nozzles to an axial line tilting downward at a constant angle against a vertical line and provide these nozzles autorotation on the axial line as an axis and revolving on the vertical line as an axis.

CONSTITUTION: A part of a pressure liquid is jetted out of each nozzle 6 passing a passing route 9, a through hole 8, and a nozzle hole 7 when the pressure liquid for cleaning is supplied to a supplying route 2. The rest of the pressure liquid in the supplying route 2 is jetted out of a nozzle 19 to rotate a turbine 18. The rotation of the turbine rotates driving gears 14 through reduction gears 16 and an outer cylinder 3 rotates on an axial line A. Owing to the rotation of the outer cylinder 3, a sleeve 5 having bevel gears 10 to be geared with bevel gears 12 is rotated on an axial line B as an axis. Consequently, the inside of a tank is cleaned effectively with a saved amount of a cleaning liquid and without vain.