To provide a cleaning sterilization apparatus capable of sterilizing an object to be cleaned such as a medical instrument effectively in a short time by generating and using ozone water containing ozone with particle diameters hard to disappear in water, the cleaning sterilization apparatus is provided with cleaning water supply means, ozone water generating means, and squirting means for squirting cleaning water and ozone water toward the object to be cleaned inside a container, where the ozone water generating means is provided with a mixing pump which takes in ozone and water to mix and generates ozone-mixed water, ozone supply means for supplying ozone to the mixing pump, stirring means for colliding the ozone-mixed water from the mixing pump sequentially with a plurality of protrusions with running-water pressure applied inside an enclosed running-water channel with the plurality of protrusions arranged therein, and thereby making ozone contained in the ozone-mixed water finer to generate ozone water, and a line mixer which causes the stirring means to circulate and stir the ozone-mixed water generated by the mixing pump and thereby adjusts particle diameters of ozone contained in the ozone-mixed water.
