PURPOSE: To narrow down abnormality factors by respectively sampling output values showing operating states with an abnormality detecting means, detecting the presence/absence of abnormality within fixed time and storing that detecting output in a storage means.

CONSTITUTION: This device is provided with an abnormality detecting part 1 for detecting abnormality from an object 10 to detect the state and a storage part 2 for storing the detecting output from the abnormality detecting part 1 at every fixed time. At an abnormal state count part 2a of the storage part 2, the presence/absence of abnormality is decided by basically comparing a count value counted within prescribed time with a previously set specified value, and the decided result concerning the presence/absence of abnormality is supplied to a FIFO part 2a corresponding to the count value within the time at every set fixed time. Then, the FIFO part 2b shifts the decided result on the left side for one bit written in advance for writing that decided result and stores it. Thus, this FIFO part 2b can store time sequential data concerning the abnormality until the stop of an applied device caused by the abnormality.