PURPOSE: To detect the abnormality which arises in a driving part or sliding part by providing a detecting means which detects the decrease in the number of continuous strokes of a press machine.

CONSTITUTION: The number of strokes in 1min decreases to a prescribed number or below when the load of the press machine increases as a result of generation of abnormality. Contacts P2 for a count-up signal are consequently not closed in 1min and the 1st auxiliary relay (CR1) does not operate. The normally closed contacts CR1 are thus held closed and the 1st time limiting relay TR1 is actuated, by which the relay contacts TR1 thereof are closed and the 2nd auxiliary relay (CR2) is actuated. The relay contacts CR2 thereof are closed and a pilot lamp R for press abnormality is lighted. The abnormality of the press is thus displayed.