A network system has a computer device, and a plurality of node devices communicatively connected to the computer device via network with one or more sensor devices allowed to be connected to each of the plurality of node devices via wireless communication. Each of the node devices obtains sensor data from the sensor device which is connected to the node device itself via the wireless communication and saves the sensor data in a sensor data storage section incorporated in the node device itself. The computer device specifies and requests via the network sensor data that any one or more of the one or more sensor devices obtained, and obtains via the network the specified sensor data from the node device which has saved the specified sensor data in the sensor data storage section among the plurality of node devices.