PURPOSE: To provide an automatic type high speed centrifugal barrel polishing machine which permits the selection of the automatic opening and closing of a polishing tank cover according to the cases: simultaneous opening of all the tanks, opening of several ranks, or each tank, and whose machine body is tiltable.

CONSTITUTION: An automatic center adjusting bearing 26 is installed on a polishing tank cover 34 equipped with a fitting frame 34a, and a polishing tank 22 which is one-side-supported by a polishing tank rotation shaft 11 in opening the cover is both- side-supported in closing the cover, allowing also the polishing tank cover 34 to serve as supporting body. The fluid as polishing tank cover opening/closing control medium flows in the fluid transport pipes 38a and 38b embedded in a revolution main shaft 12 by a fluid cylinder 23a, and converges with a transport pipe connected with a fluid storage control mechanism, in the fluid transport grooves 31a and 31b in a can body 31 which is cut by interposing a fluid shielding member between the grooves. A machine body case 17 is fixed at a set angle by a supporting seat 40 which is tilting pivotally supported and an auxiliary supporting seat 41 extended from the supporting seat.