An injection mold for a light guide body is disclosed which comprises: a cavity defined inside the injection mold to provide a contour of the light guide body; a plurality of through holes each of which communicates with the cavity, allows an optical fiber to be inserted in the through hole, and has a portion at which the optical fiber is clamped; and a first mold and a second mold having a first groove and a second groove for each through hole, respectively, which first and second grooves are adapted to mate and form the through hole when the first mold and second molds are joined together for injection molding with the fiber clamped, wherein at least one of opposed portions in the first and second grooves corresponding to the portion of at least one of the through holes at which the optical fiber is clamped is made of an elastic material.