PURPOSE: To uniformly deburr the overall surface of a workpiece by revolving as well as rotating, through rotating and revolving means, a holding member which holds the workpieces in a container that contains viscous working fluid mixed with abrasive grains.

CONSTITUTION: A magnet-field adding means with a built-in doughnut-like container 22 is positioned and set on a bench drilling machine 31, and respective workpieces W held on chucks 12a are dipped into viscous working fluid 27 mixed with abrasive grains by actuation of cylinders 8a. When a revolving plate 6 is revolved through a drill chuck 4, the workpieces W held on the chucks 12a are respectively rotated as well as revolved in the container 22 through V belts 14, 15, pulleys 13a, and driven shafts 7a, and a magnetic field is added through a coil 23 to cancel the deviation caused by the centrifugal force of the working fluid 27 mixed also with magnetic powder, thereby resulting in uniform deburring. The workpieces, even they are plural, can be thus uniformly deburred on overall surface with an uniform finish.