To efficiently display a situation in a luggage compartment of a vehicle without obstructing the driving action of a driver.

A situation analysis part 18 analyzing the situation in the luggage compartment based on an image acquired by a camera 13 and the detected information of a sensor 17, issues a warning unconditionally when abnormality information of the sensor 17 or the large difference between frames by a large behavior is present and issues the warning to a small behavior only when an occurring cause or an occurring place is specified.