A portable operation interface transmits an instruction to switch an operation mode to a stacker crane with an automatic operation mode and a manual operation mode via a first wireless communication route. A second receiver is connected to the stacker crane. For example, a portable operation interface including a portable remote controller wirelessly transmits to the second receiver a connection request to establish wireless communication in the second wireless communication route. The second wireless communication route is a different route from the first wireless communication route. The second receiver that receives the connection request determines whether a first condition that the stacker crane is in the manual operation mode is satisfied. The second receiver establishes wireless communication via the second wireless communication route with the portable operation interface when it is determined that the first condition is satisfied.