There is provided a sterilization apparatus for sterilizing an object. The sterilization apparatus includes a concentration chamber configured to concentrate sterilizer, a vaporizing chamber configured to vaporize the sterilizer, a measuring pipe into which the sterilizer is introduced from the concentration chamber before being introduced into the vaporizing chamber, a vacuuming device configured to vacuum the sterilization chamber, and a first valve configured to be opened and closed to control communication between the sterilization chamber and the measuring pipe, wherein after the sterilizer is introduced from the concentration chamber into the measuring pipe, gas contained in the measuring pipe is removed from the measuring pipe by opening the first valve.