Vehicle interior monitoring device

A vehicle interior monitoring device (100) monitors the interior of a vehicle (Va) in a parked state. A vehicle interior monitoring device is provided with a biological detection unit (110), an environment determination unit (120), an environment improvement unit (130), and a remaining amount determination unit (140). The organism detection unit detects an organism (P) remaining in the vehicle interior. When a living being is detected, the environment determination unit determines whether or not there has occurred an environment deterioration in the vehicle interior that is not preferred for the living being. The environment improvement unit drives at least one of the high power improvement device (21) and the low power improvement device (31) when it is determined that deterioration of the environment in the vehicle interior has occurred. The remaining amount determination unit determines a decrease in the remaining amount of the battery (92). When it is determined that the environmental deterioration in the