A security system includes a camera that captures an image of a monitoring area, a recorder that stores the captured image which is captured by the camera, a sensor that detects a matter in the monitoring area, a video monitoring and display device that causes a monitor to display the captured image of the monitoring area from the camera or the recorder, and a BLE reception device that detects a signal from a BLE transmission terminal which is installed or maintained by a guard who patrols the monitoring area. In a case where the matter is detected in the monitoring area, the video monitoring and display device extracts the captured images of the suspect or the guard, chronologically arranges the captured images, and displays the captured images on the monitor. Furthermore, in a case where the video monitoring and display device displays the captured images of the guard, the video monitoring and display device also displays positional information of the BLE transmission terminal in association with the captured images of the guard.