A device and method for monitoring and correcting the position and orientation of an operating device (2) with respect to a piece (P). A measuring device (5) including a plurality of sensors (505) connected to the operating device is used to measure through contactless technology the distances of the sensors from a surface (π) of the piece along respective directions (l, r, s) having given orientations. The sensor measurements are compared to predetermined desired values and the position of the operating device (2) is selectively changed to maintain a desired positional relationship between a main operative axis (X1) of the operative device and operation axis (X2) defined by the surface of the piece.