Abstract: A surface mounting package includes a metal base with a lower surface having a through hole, a metal lead arranged to be inserted into the through hole, an insulating material arranged at an internal space of the metal base, a cap covering the metal base as a lid, and an electronic part component arranged at a surface of the metal lead that is positioned at the internal space of the metal base. The internal space is held at an air-tight atmosphere. The metal lead forms a surface for attaching the metal base to a mounting board. An insulation distance between the metal lead and the metal base is at least 0.05 mm and at most 0.3 mm.

Abstract: An object is to provide a thermal fuse that is free of a trouble of welding contact between a movable electrode (4) and a lead (2) even when temperature of an equipment to which the thermal fuse is connected rises gradually and that has small electric resistance at the time of conduction.