A monitoring system includes electric devices, communication adaptors communicably connecting the electric devices with a network, and a monitoring device monitoring the status of each electric device. The monitoring device acquires from user input a type of running indicating whether or not the status of the electric device is always ON. The monitoring device transmits to each electric device a status acquisition request requesting acquisition of the status of the electric device. Then the monitoring device determines the status of the electric device based on a response to the transmitted status acquisition request and the acquired type of running.