PURPOSE: To provide a step breakage sensing device which seness breakage of escalator steps automatically.

CONSTITUTION: A step breakage sensing device for escalator has a TV camera 7, which is installed inside a lower truss part 5 to photograph steps 2 in movement. A control device 11 senses each step 2 in movement using the output of a photo-sensor 14 where it has reached the field of view of the TV camera 7, and image processing signal is fed to an image converter 8 so that the photographed image of the step 2 is subjected to a converting process into an electric signal. The processed image signal is sent to a control board 10 via an I/O board 9. The control board 10 compares the photographed image of each step 2 with normal step form which has been stored in advance, judges if any failure exists in the step 2, and displays failed step in a display device 18.