To provide an alloy for thermal fuse operating at about 100°C which is free from Cd and Pb adversely affecting a human body and also is decreased in a difference between a solidus temperature and a peak temperature and further has excellent workability.

As the alloy for thermal fuse for use at 95 to 105°C fusing temperature, an alloy for thermal fuse having a composition consisting of, by mass, 51 to 53% In, 6 to 8% Bi, 0.5 to 1.5% Zn and the balance Sn is used. In order to suppress the change with the lapse of time, ≤0.05 mass%, in total, of Al, Ge and Ga can be added. The alloy for thermal fuse is free from Cd and Pb adversely affecting a human body, and further, the difference between the solidus temperature and the peak temperature which determines the operability of the thermal fuse is small. Moreover, because of its elongation, the alloy for thermal fuse is highly advantageous in workability into a fine wire.