Abstract: A machine tool installation (1) for the processing of workpieces includes encompasses a work area (4) for the machining of workpieces and contains a workpiece support (13), a work area enclosure (3) featuring a gate (7) and at least one corresponding door segment (6/1, 6/2, 6/3) which can be moved in the horizontal direction between open and closed positions and is supported on the substructure of the machine installation (1) in horizontally movable fashion. Provided above the substructure of the machine tool installation (1), and attached solely to the workpiece support (13) is at least one stationary guide element (14, 15) for the door segments (6/1, 6/2, 6/3) and extending over at least part of the width of the gate.