A method of butting and connecting a first optical fiber and a second optical fiber in an optical connector comprises placing said optical connector that holds said first optical fiber in wherein an optical fiber connection tool; mounting said optical fiber holder on a holder mounting base of a front end bevel processing tool; processing a front end face of said second optical fiber such that said front end face of said second optical fiber is beveled relative to the surface perpendicular to the optical fiber axis direction; transferring said optical fiber holder to said holder support base; and moving said optical fiber holder toward said optical connector along said guide part, and butting and connecting the beveled front end face of said second optical fiber to the front end face of said first optical fiber such that their bevel directions are aligned.