A plurality of data output apparatuses (10) are installed at places different from each other, and each output data in wireless communication. A data storage apparatus (20) stores the data output from the data output apparatus (10). The data output apparatus (10) includes at least one sensor and a wireless communication apparatus. The wireless communication apparatus stores, for each of the plurality of other wireless communication apparatuses that can be a transmission destination of the data, connection information for connecting to the other wireless communication apparatus and priority information indicating a priority of the other wireless communication apparatus. Then, the wireless communication apparatus repeats processing of reading the connection information, and performing communication by using the read connection information in descending order of the priority until the communication succeeds when a transmission route of the data is set.