To suppress interference of the peripheral edge of a through hole of a work support cover, into which hole a die enters in machining, with a work in conveying.

In a shutter switching mechanism S provided at the side of an under turret 13, three brush shutters 77, 79, 80 are integrally movable by an electric actuator 103. The brush shutters 77, 79, 80 are provided respectively with through holes 85a and 85b, 87a, 88a, which correspond to the outer diameters of lifter pipes for holding dies D used in machining, on base plates 85, 87, 88, and provided with brushes 81, 83, 84 on the base plates 85, 87, 88. By moving the brush shutters onto the dies D indexed and positioned to machining positions and then lifting the brush shutters corresponding to the dies D (lifter pipes) to be used in machining, the brush shutters are made to enter openings 31a of a fixed table 31, and the upper edges of the brushes are aligned with a pass line PL of a work W.