A device for controlling a elevator installation with multiple deck cars which are simultaneously accessible at a main stopping point by different main stopping floors includes a call registering device by which a passenger can input a destination floor. In order to enable a more rapid filling of the building, a conversion unit responds to the destination call travel orders already allocated to and/or demanded of the multiple car having the deck which is to be allocated to the passenger to minimize the number of stops of the car. An indicating device indicates to the passenger the allocated car deck and/or the main stopping floor thereof.