PURPOSE: To safely and surely open a door, when an obstacle is present, by constituting a device previously recording, when no obstacle is present of a passenger or the like, an electric pattern compared with the electric pattern, when the obstacle is present, with a compared output signal operating a door driving gear.

CONSTITUTION: A safety capacitance electric pattern between an antenna 15 and an earth part 16, when no obstacle is present between doors opened and closed, is previously detected and stored in a memory device 30. Next, a capacitance electric pattern between doors opened and closed, during operation, is detected. A comparator 21 compares this stored capacitance electric pattern with the detected capacitance electric pattern with a capacitance change of that pattern driving and controlling an elevator door driving gear 22. As a result, when the obstacle is present, the door can be safely and surely opened even with the electric pattern changed following the door opened and closed.