Method for producing imaging lens unit and imaging lens unit

The objective of the present invention is to provide a method for producing an imaging lens unit (100), said method being able to: easily connect a holder body and a cover without increasing the number of parts; cause the imaging lens unit (100) to be more compact; and avoid degradation of dimensional precision, problems with specifications of outer appearance, the occurrence of flares and ghosting stemming from positioning shape, and the like. In a second molding step, by means of performing additional molding on a first holder member (20) in which the lens (10) has been inserted, the separation of the lens (10) is prevented and the lens (10) is fitted to the first holder member (20), and a welded second holder member (30) is molded. As a result, it is possible to reliably perform molding of the second holder member (30) and joining to the first holder member (20) at once, and thus situations such as an increase in the number of components for assembling the holder can be avoided.