To provide a thermal fuse having an improved workability by avoiding chemical activity of halogen element exerting bad effect on the environment, and by widening the range of material selection.

Halogen-free flux 5 is used for a flux film 5 covering the surface of the low melting point fusible alloy 4. An electrode part 1a is formed to the top end part of a pair of lead members 1 respectively. The thermal fuse comprises a fusible alloy assembly formed by arranging the low melting point fusible alloy 4 covered by the flux film 5 so as to form a bridge between the electrode parts 1a, and a package formed by joining a cap member 2 made of resin having insulation property to a case main body 3 and sealing by adhesive 7. The main part of the fusible alloy assembly is packaged and halogen-free non-active or slightly active flux is used for the flux film 5.