To provide a workpiece fixing device having a ferromagnetic part capable of preventing an increase in rotation load on a conveyor without using an electromagnet that is movable.

This workpiece fixing device comprises a plurality of placement boards 11 where workpieces 1 having ferromagnetic parts are placed, a carrying device 10 to endlessly connect the plurality of placement boards 11 to each other to be circulated, magnets 15 fixed to prescribed positions in the carrying device to fix the workpieces carried on the carrying device on the placement boards by a magnetic force, and an interval holding part 11 comprising non-magnetic material to hold a constant distance between the magnet 15 and the workpiece 1. The workpiece 1 is fixed by means of the magnet when it is processed by a processing head. Processing is completed, and it is moved to a place where it is beyond the magnetic force of the magnet 15, so that it can be removed easily. Since the magnets are fixed, they are not loads for carrying.