GAS SUBSTITUTION DEVICE

The present invention has been made in an effort to more assuredly substitute oxygen in a vial. A gas substitution apparatus according to the exemplary embodiment of the present invention includes: a first gas substitution unit which seals a periphery of an opening of a vial disposed in a gas substitution section, and guides a flow of a first substitution gas to be supplied into the vial; and a second gas substitution unit which is coupled to an upper side of the first gas substitution unit, and guides a flow of a second substitution gas to be supplied directly into the vial.