To improve the working efficiency for a work by simultaneously executing working a V-groove and bending with one device without using another device for working the V-groove.

This device has a top die 31 which is vertically movable, bottom die 32 which is stationed just under the top die 31, coining dies 50 which are provided freely fixably and releasably on the top die 31 and with which the V-grooves are worked on the upside of the work W by pressing the work W between itselves and the bottom die 32 with lowering of the top die 31 and bending beam 33 for bending the work W on which the V-grooves are worked with the coining dies 50.