To provide a safety device of a door capable of surely preventing a pulling-in accident, without generating a detection miss and unnecessary operation.

Frame body both side walls of a car are provided with a light sensor 6 for setting a clearance area between a door 2a and a door 2b to a detecting area, and a light sensor 7 for setting a clearance area between the door 2b and a wing wall 4 as a detecting area. A doorway column 3 and the wing wall 4 are provided with a light sensor 8 for setting an area on this side (the car side) of the door 2b as a detecting area. When the doors 2a and 2b are closed, when any of the light sensors 6, 7 and 8 detects an obstacle, for example, hands of a passenger, a warning and a caution are issued, and when detecting the hands of the passenger in opening operation of the doors 2a and 2b, the opening operation is stopped once.