Abstract: A burring processing method for performing burring processing for a metallic pipe 90 within a short time to provide a beautifully finished appearance. A jig with an inclined section 15 is inserted into the inside of the metallic pipe 90 with a prepared hole 91. After the jig and the metallic pipe 90 are fixed in a state that the inclined section 15 of the jig is aligned with the prepared hole 91, steel balls 41 having a diameter greater than that of the prepared hole 91 are pressed against the inclined section 15 inside the metallic pipe 90 so that the steel ball 41 is pushed from under the prepared hole 91 to the outside of the metallic pipe 90.