PROBLEM TO BE SOLVED: To disinfect a preform simply and rapidly.SOLUTION: A number of preforms (1) formed to be a bottom cylindrical shape are input on a conveyor (4), made into an irregular recumbent state, while the preforms are made to pass in a first chamber (5) by the conveyor, heating air (H) is sprayed to the preforms (1) from both sides of the conveyor to preheat the preforms (1), continuously while the preforms are made to pass in a second chamber (6) by the conveyor, super heated steam (S) made from water in which hydrogen peroxide is mixed is sprayed to the preforms from both sides of the conveyor to disinfect the preforms (1).
