A particle feed apparatus is combined with a jet mill and has a particle feeder for feeding particles to an air injector that injects particles together with particle carrying air into the jet mill. The particle feed apparatus is a closed structure isolated from the environment. The use of the closed particle feed apparatus prevents the backflow of dust-loaded air that occurs in a milling system formed by combining a jet mill and an open particle feed apparatus. The use of the closed particle feed apparatus improves the working environment, enhances the milling ability of the jet mill and facilitates operations.