PROBLEM TO BE SOLVED: To provide a cap sterilizer easy to change cap sterilization time, a cap sterilizer easy for maintenance by downsizing a machine, and further a cap sterilizer easy to develop from low to high performance.SOLUTION: The cap sterilizer 1 for sterilizing a cap to be put on a bottle mouth or the like during conveyance includes: a first cap interval determining device 13 for feeding caps 10 supplied from upstream at constantly indexed intervals a first chute 20 for conveying the caps 10 fed from the first cap interval determining device 13 by driving force by a jet of a fluid from a fluid jet device and a second cap interval determining device 17 for feeding the caps 10 fed from the first chute 20 at constantly indexed intervals.
