The copy-milling device (1) for the manufacture of especially dentistry workpieces has a arm (4) pivotable around a horizontal axis normal to its longitudinal direction and with a motor powered cutting tool (5) for the forming of a workpiece from the blank, and a sensing device (6) for the scanning of the model piece. The cutting tool and the sensing device are connected to move mechanically and synchronously. A suspension device is provided for the arm and has a weight compensating spring (11) acting between the arm and an abutment (12) installed on the copy-milling device above the arm. Independent claims are included for the following: (A) a method for the operating of a manually guided copy-milling device which entails applying the force required for the positional change of the cutting tool or sensing device at least partially directly on the motor powered cutting tool; (B) a support plate for a copy-milling device which has at least one through-hole arranged in such a way that the dust created during milling of the blank passes through it; and (C) a holding element for a support plate with a housing for a blank and a through-hole.