A ventilation and deodorization system includes a door lock switching unit for performing a locking and an unlocking of a vehicle door, an air conditioner which introduces outside air of a passenger compartment of the vehicle and blows the introduced outside air into the passenger compartment in a ventilation operation, and a control device for controlling its operation. When a door unlocking request signal is received as a remote operation signal by a receiving unit, the door lock switching unit performs the unlocking of the vehicle door, and the air conditioner performs the ventilation operation. Alternatively, an air cleaning operation is performed instead of the ventilation operation, while inside air of the passenger compartment is cleaned and circulated by an air cleaning device. Thus, the ventilation operation or the air cleaning operation can be performed while a battery consumption amount can be reduced.