It is possible to provide a user with progress information of an unattended object after the appearance in a monitoring area. An unattended object monitoring device is configured to include an image acquirer that acquires a captured image of the monitoring area imaged by the imaging device, an object tracker that detects an object appearing in the monitoring area from the captured image and tracks between the captured images for each appearing object, an unattended object detector that detects an appearing object not displaced beyond a predetermined time as an unattended object based on a tracking result for each appearing object, a progress information generator that generates progress information of the unattended object after the appearance in monitoring area based on the tracking result for each appearing object, and a notification image generator that generates notification image by superimposing the progress information on the captured image.