PROBLEM TO BE SOLVED: To provide a plasma sterilizer evenly sterilizing the whole surface of an object to be sterilized, having an irregular three-dimensional shape, and capable of sterilizing without damaging the object to be sterilized.SOLUTION: The plasma sterilizer has a construction including: an electrode part 1 where a plurality of electrodes are arranged at intervals transportation means 2 for transporting an object to be sterilized on the electrode part 1 and application means 3 for applying a high-frequency voltage to each of the electrodes forming the electrode part 1 so that the electrodes (electrodes 1a and 1b) adjacent to each other in the electrodes forming the electrode part 1 have different polarities. The object to be sterilized is sterilized without being damaged by bringing a high-frequency voltage applied to each of the electrodes by the application means 3 to an electrical potential level causing no electric discharge between the electrodes adjacent to each other, and an electrical potential level generating plasma electric discharge in the case where the object 100 to be sterilized crosses over between the electrodes adjacent to each other.
