A monitoring device (2) identifies an object from videos made by a plurality of cameras (1) including a first camera and a second camera and having a predetermined positional relationship. The monitoring device has a receiving unit (21) configured to receive the videos from the plurality of cameras, a storage unit (22b, 22c) configured to store feature information indicating a feature of the object and camera placement information indicating placement positions of the cameras, and a controller (23) configured to identify the object from the videos based on the feature information. If an object has been identifiable from the video made by the first camera but has been unidentifiable from the video made by the second camera, the controller (23) specifies, based on the camera placement information, the object in the video made by the second camera.