To machine a bent outline of a work by providing claw connecting parts for rotating a spindle reciprocating table together with work spindles to be supported to the upper part in the disconnecting state and connecting spindle driving parts to the work spindles in the connecting state.

A brake device is provided on spindle driving devices 13b to 13d or work spindles 9b to 9d. Claw connecting parts 12b, 12c, 12d can be connected to and disconnected from one another by the axial movement of their connecting half parts. In the connecting state, the claw connecting parts 12b to 12d transmit force from the spindle driving parts 13b to 13d to the work spindles 9b to 9d. On the other hand, in the disconnecting state, the claw connecting parts 12b to 12d disconnect the ends to be driven of the spindle driving parts 13b to 13d from the work spindles 8b to 9d, and a spindle reciprocating stand 7 can be rotated around an indexing shaft 8.