PURPOSE: To facilitate confirmation of whether or not a device is normally operated by a method wherein during waiting of a press machine, a shielding and optical axis abnormal state producing circuit is driven by means of an output signal from a self check start circuit under waiting, and a state wherein two or more of a plurality of beam axes are simultaneously shielded is produced in a pseudo-manner.

CONSTITUTION: By means of an output from a self check start circuit 7 under waiting, self-checking of a beam type safety device 1 by a self check circuit 2 is started. Namely, a false signal by which a beam axis abnormal state is produced at each of a plurality of beam axes of a beam type safety device 1 is orderly inputted to the beam type safety device 1. In this way, a shield state is generated in a pseudo manner at every one beam and it is confirmed about all beams axes that the beam type safety device is normally operated in a pseudo shield state. In this case, an optic axis shield light circuit and an abnormal state producing circuit 11 are simultaneously started, a shield detecting signal is outputted from the beam type safety device 1 to confirm whether or not a rapid stop circuit 5 is normally operated.