A structure of a joint box for a linear type processing optical cable is provided to facilitate moving a core wire between remainder boards by forming an optical fiber drawing out part of the remainder board into drawing out structure of 4 directions. A cable gripping part is formed inside both ends of a back case(105). The cable gripping part adamantly holds a cable central strength component. A remainder board supporting part(110) is built inside the back case. The remainder board supporting part is opened at the angle of 90 deg. in connection operation. A remainder board(140) is formed owing to a pair of first through-hole and a second through-hole into drawing out structure of 4 directions. One or more locking devices are formed on the top of a front case(100) and the back case. The locking device part locks and unlocks the front side case and the back case.
