A plurality of external electrodes 11c, 11m are disposed in parallel along two sides facing each other of a region 300 corresponding to the circuit substrate to be manufactured, and a probing electrode is formed, which is connected to the external electrodes through extending conductors 13a, 13b extending to the outside the region 300 from the external electrodes. At this time, widths of the extending conductors 13a, 13b are set smaller than the widths of the external electrodes 11c, 11m and probing electrodes 12a, 12b. Therefore, a solder storage part is formed in a wide portion in a width changing part between an electrode and a conductor, and a necessary sufficient amount of solder is adhered to the surfaces of the external electrodes 11c, 11m.