A device is provided, comprising: an image storage unit which is configured to store image data obtained by a monitoring camera; an obtaining unit which is configured to obtain an alert signal which occurs depending on a situation in a monitored region; and a transmitting unit which is configured to transmit alert corresponding information which includes a content of the alert signal and any one of in-the-period image data in a reference duration including an occurrence time of the alert signal among image data stored in the image storage unit or an address of the in-the-period image data in the image storage unit to a file server accessible to another apparatus different from the device.