PURPOSE: To provide a display for abnormality informing easily an operator of a content of abnormality by a low costed structure when the abnormality is generated in a machine.

CONSTITUTION: When an abnormality of a machine is detected with detectors 11a, 11b, an LED lamp 12 informing an operator of occurrence of abnormality is lit. When a display changing switch 13 is operated at that time, a signal is outputted to a display selecting means 15 from a control part 8. A display signal corresponding to a content of the abnormality is selected to be read from a display signal storing means 14, which is displayed by a combination of a character and a numeric on a display 10. A position of the abnormality and its content are confirmed by a corresponding table explaining details of the abnormality corresponding to the combination.