PURPOSE: To transport load efficiently, safely and surely by constituting an elevator door controller so that the same floor stop of a cage in the interlocking operation other than a specific master car is detected and the door opening operation is controlled when a door opening button of the master car is operated.

CONSTITUTION: When a same floor stop detection relay 5 detects the stop of the A and B machines on a same floor, for example, in case of stop on the fourth floor, the A and B machines close the respective floor switches 4F, and the same floor stop detection relay 5 is energized in the circuit (+)-(4F-A)-(4F- B)-(4b-B)-(2b)-(5)-(-). In the A machine, if a B machine door opening instruction lamp lights up and a door opening button is pressed, the door of the B machine opens. When loads are loaded on the A and B machines whose doors are opened, and transported, the cages on which loading is completed are transported to the destination floors in succession, and an operator gets on the A machine which is designated as master car reaches the destination floor, and when the door pushing button of the master car is pushed, the door is opened. Accordingly, each cage in interlocking operation is prevented from being opened inadvertently at the destination floor, and safety is secured.