Provided is a wireless device and a wireless network capable of readily communicating wirelessly using different frequency bands and wireless formats to match the state of wireless communication at the installation location of the facility being monitored. A wireless device for performing wireless communication using a wireless module suited to the state of communication, the wireless device being provided with a plurality of wireless modules on a base substrate, wherein the wireless modules are a plurality of wireless modules between which the frequency and/or the wireless format differ. The wireless device is characterized in being provided with: a device controller for selecting a wireless module suited to the state of communication, the device controller being detachably mounted on the base substrate and connected to the plurality of wireless modules by signal wires; and a terminal block for external connection and a communication interface, which are connected to the device controller. The wireless device performs wireless data communication using a wireless module selected by the device controller, the data being acquired from the terminal block or the communication interface.