The present invention makes it possible to easily ascertain whether an abnormality is present at any location of a hoop member by which a resin part is insert-molded. An injection-molding machine comprises: an elongated hoop member (4) by which a resin part is insert-molded by packing a molten resin into a closed die in a state sandwiched between dies; a molding conditions detection sensor (31) for detecting that there is an abnormality when a predetermined condition during insert molding has departed from the predetermined condition; and a hoop member operating distance detection sensor (32) for detecting the position of the hoop member (4)by which a resin part(35) is insert-molded, when an abnormality has been detected by the molding conditions detection sensor (31). When a departure from the predetermined condition has happened, the molding conditions detection sensor (31) detects that an abnormality has occurred on the basis thereof, and the hoop member operating distance detection sensor (32) detects the position of the hoop member (4) by which the resin part (35) has been insert-molded when the abnormality occurred.