Abstract: A method and an apparatus are described for the production of a mitered corner joint between parts of a frame, by vibration welding. During the welding procedure, in each case two parts of a frame are displaced by oscillatory heads into mutually perpendicular straight-line translatorial oscillations, the phases of which have been matched to one another in such a way that mitered areas of the two parts of the frame oscillate perpendicularly with respect to a stationary mitered plane and through the same, while the mitered area is retained under a prescribed welding pressure in the system. The method and the apparatus can be used for the simultaneous production of the four corner joints of a frame, in particular of a frame of the moveable or fixed part of windows or of doors. For this, at least four, and preferably eight, oscillatory heads, which displace the parts of the frame into the translatorial oscillations, are synchronized in such a way that their frequencies and amplitudes are the same.