Temp. fuse, battery and temp. fuse mfg. method

A thermal fuse reduced in size and thickness can be obtained. Further, the thermal fuse will not be degraded in characteristics, productivity, reliability, quality, etc. even after reduction in size and thickness. The thermal fuse includes a fuse main body including a substrate, a fusible metal and a cover, and paired terminals disposed protruding from the fuse main body. The other end of the first terminal has a first fusible metal connection, and the other end of the second terminal has a second fusible metal connection. The fusible metal is disposed between the first terminal and the second terminal, and one end of the fusible metal is connected to the first fusible metal connection, and the other end of the fusible metal is connected to the second fusible metal connection. The cover is disposed so as to cover the fusible metal, the first fusible metal connection, and the second fusible metal connection. Length L1 and thickness L3 of the fuse main body located between the first terminal and the second terminal are respectively in the ranges of 2.0 mm