Fastening of a vehicle roof antenna by means of a clamping part

To provide a manufacturing method and apparatus for an electrical component with a metal casing that can efficiently manufacture a highly reliable electrical component with a metal casing, without damaging the parts mounted on a substrate when soldering the metal casing onto the substrate.A metal casing 5 is set on a solder composite (solder paste) 4a applied onto a land 6 for fixing a metal casing, a heating means 25 (14) is brought into contact mainly with the top surface of the metal casing, the metal casing is heated more than the melting point of the solder to melt the solder in the solder composite applied onto the land, and the metal casing 5 and the land 6 are joined. Further, the heating means 25 may be structured such that it is composed of a heat generator 13 and a heat transmitter 14 for transmitting heat from the heat generator to the metal casing, so that the heat generator and the heat transmitter are separable to shorten the heating/cooling cycle time as well as enabling the heat transmitter 14 to be cooled off while being pressed to the metal casing 5 after having soldered the metal casing.