RECTANGULAR SECONDARY BATTERY

A prismatic secondary battery according to the present invention has a problem of providing a highly reliable the prismatic secondary battery by securing both mechanical strength and electrical characteristics between a metal body to which a bus bar of an external terminal is welded and a connection terminal which is joined with the metal body. In a prismatic secondary battery (100A) of the present invention to solve the above-described problem, external terminals (141 and 151) of a positive electrode and a negative electrode are disposed on one surface of a prismatic battery container (101) and a flat wound group is housed in the battery container. One external terminal (151) has a connection terminal (153), which passes through the battery container and is electrically connected to the flat wound group (170) and a metal body (152) which is joined with the connection terminal, and joints between the connection terminal and the metal body include a mechanical joint and a metallurgical joint.