PURPOSE: To make an operator instructible so easily, by installing an instruction inputting device, an operational device, a preliminary performing device, an actual position data detecting device, a limit operational device and a main performing device all in a controller for a grinder operation robot device grinding a flash or the like for removal.

CONSTITUTION: A grinding operation robot device 1 consists of a rectangular coordinate type robot 2 having X, Y and Z axes, a grinder 3 attached to its wrist part 2a, a reaction force detector 4 built in this grinder 3 and a controller 5. This controller 5 is provided with an instruction inputting function instructed for an instruction starting point and an instruction ending point from an operator and an operational function calculating position control data of each degree of freedom of the robot so as to cause a grinding wheel 3a to move along a path between the instruction starting point and the instruction ending point. In addition, the controller 5 is provided with a preliminary performing device performing preliminary drinding operation, an actual position data operational function securing position data of both actual starting and ending points, an operation limit operational function and a main performing function performing main grinding operation.