To reduce the number of inverter, to miniaturize a crane, and to save the electricity by inserting an AC/DC converter and DC/AC converters arranged in the same heat sink into a route for transmitting the electric energy to a traveling motor and a fork lifting motor of a stacker crane for connection.

A stacker crane to be used for automatic warehouse is provided with a traveling motor 1 and a fork lifting motor 2, and DC/AC inverters 3, 4 are connected to each motor 1, 2. On the other hand, an AC/DC converter 6 provided in the ground as a fixed side is connected to an alternating current power source 5, and a battery 7 is connected to this AC/DC converter 6, and the DC/AC inverters 3, 4 are connected to the AC/DC converter 6 through duct shoes. With this structure, the AC/DC converter 6 and the DC/AC inverters 3, 4 are arranged on the same heat sink 8.