A biological signal acquirer is attached to a subject and acquires a biological signal of the subject. A transmitter carried by the subject transmits the biological signal. A first communication port and a first camera are installed in a first location and connectable to a network. A second communication port and a second camera are installed in a second location and connectable to the network. A biological information acquiring device is connectable to the network and provided with a switcher. The switcher acquires, when communication establishment between the transmitter and the first communication port is detected, the biological signal through the first communication port as well as a first image taken by the first camera, and acquires, when communication establishment between the transmitter and the second communication port is detected, the biological signal through the second communication port as well as a second image taken by the second camera.