PURPOSE: To detect the blurring of a camera in a short processing time with simple constitution.

CONSTITUTION: A sensor simple substance outputs with sensor pitch equivalent to a blurring quantity which is allowable on a film surface, and output from plural sensors 101-10n which is much smaller than the sensor pitch is stored in a 1st storage part 16, and it is stored in the storage part 16 again after the interval of specified time which is counted by a timer circuit 18. A maximum and minimum position detection circuit 22 compares amounts stored in the storage part 16 at the respective points of time with one another, and detects a sensor number (position) where the output of the sensor simple substance is maximum and minimum, then the detected result is stored in a 2nd storage circuit 24. By judging whether the newest maximum and the minimum sensor numbers (positions) stored in the storage circuit 24 are simultaneously changed (moved) or not, a movement detection circuit 26 detects whether the blurring equal to or above an allowable quantity occurs in the camera or not.