To effectively monitor an object area to be monitored by a monitoring system which monitors the area to be monitored.

The monitoring system has a monitoring device 1 which captures an image of the area to be monitored and a monitoring terminal device 2 which displays the image captured by the monitoring device 1. In the monitoring device 1, an imaging unit 11 captures an image of the area to be monitored, and an image transmitting unit 16 transmits the image captured by the imaging means to a monitoring terminal. The monitoring terminal receives the images by an image receiving means, and an enlarged image display unit displays at least two enlarged images included in the images received by the image receiving means on one screen.