PROBLEM TO BE SOLVED: To provide a steam pasteurizer capable of supplying water into a chamber in a state that the temperature of a heater is high.SOLUTION: The steam pasteurizer 1 is equipped with the chamber 10 which houses an object to be pasteurized and a heater 12 for heating the water supplied into the chamber 10. The object to be pasteurized is pasteurized by the steam generated by heating the water in the same by the heater 12. The steam pasteurizer is equipped with an upper limit water level sensor 14 for detecting the water level in the chamber 10 and a control part for controlling the operation of the steam pasteurizer 1. The control part stops the supply of water to the chamber 10 corresponding to the water level in the chamber 10 detected by the upper limit water level sensor 14. The control part continues the supply of water to the chamber 10 for a predetermined time after the start of the supply of water to the chamber 10 regardless of the detection of the water level in the chamber 10 by the upper limit water level sensor 14.
