PURPOSE: To automatically and efficiently deodorize a passenger room after parking for a predetermined time, by outputting a parking confirming signal to a timer circuit when an engine stop time reaches the predetermined time and supplying driving power to a finely pulverizing means from a battery body only for a definite time.

CONSTITUTION: At the stop time of an engine, the detection part of a detection apparatus 50 is released from pressing due to a key. A time monitor circuit 60 operates a timer in timing bringing the output signal of the detection apparatus 50 to a low level from a high level and, when the output signal of the detection apparatus 50 does not reach a high level within a predetermined time, a high level parking confirming signal is outputted to a timer circuit 40 at the point of time when a timer operating time is elapsed to a certain degree. The timer circuit 40 receives said signal to operate and connects an input side and an output side for a definite time to supply driving power to a motor 21 and a heat generator 33 from a battery 70. By this method, a deodorizing liquid is heated and evaporated by the heat generator 33 and the formed vapor is mixed with inflow air by the wind pressure formed by a fan and sent out from an air blow-out port to be diffused into a passenger room of the vehicle.