To provide a simple structural and nature-friendly deodorizing device requiring no electric power, taking the initiative in the energy-saving time although deodorization of toilet has depended on a ventilation fan or a costly motor-driven filter deodorization device heretofor.

The power source is obtained from a water tank in a toilet. The water tank of the flush toilet is hermetically sealed. A suction force is brought in the inside of the tank when the tank is evacuated during use of the flush toilet. This force is used for deodorization. Odor gas sucked from the toilet bowl to the water tank through an air pipe is compressed by the moisture in the water tank and increase of the water level due to supply of city water and the odor gas is dissolved into water. When the tank is filled with water, the remaining air contains fragrance of a perfume from a perfume bottle and returns to the toilet bowl as a pleasant scent.