PURPOSE: To efficiently check the normal operation of input parts by selectively manually operating plural input parts such as a switch and a sensor, etc., in a check mode and allowing a buzzer to sound when a state is changed, thereby informing an operator of the normal operation of the input parts.

CONSTITUTION: In the check mode for the input parts of a plate making machine, the operator operates the input parts which are regarded as being out of order or whose operation is to be checked so as to perform on-operation or off-operation. Then, the switch 22a is turned on from an off-state. When the switch 22a acts correctly, as a result, a CPU 32 detects the change and allows the buzzer 33 to sound. To take the example of an actual plate making machine, 30 or more pieces of parts are objects to be checked. Therefore, the buzzer 33 is allowed to sound for a short time when the state of the switch 22a is changed. Thus, the operator surely confirms the result of the operation by the sounding of the buzzer 33, and the checking the input parts in the case of maintenance or failure is easily performed.