A management device is a management device to which a plurality of monitors are connected and which manages information regarding the plurality of monitors, the management device transmitting a signal for causing a screen of a first monitor to blink with a predetermined blinking pattern and setting the first monitor and a second monitor in the same group in a case where a signal indicating that an illuminance sensor corresponding to the second monitor detects the blinking pattern emitted from the screen of the first monitor is received, and the management device transmitting a signal for causing a screen of a third monitor to blink with the predetermined blinking pattern in a case where a signal indicating that an illuminance sensor corresponding to the third monitor detects the blinking pattern emitted from the screen of the first monitor is not received.