The present invention relates toa prismatic secondary battery having an external terminal and a terminal plate that are mechanically and electrically connected by a crimped portion and by a weld portion with high energy beams, in which the joining strength between the external terminal and the terminal plate is strong, internal resistance variations are suppressed, and reliability is improved. A crimped portion (17e) of a positive electrode external terminal (17) is crimped on its upper end side to be electrically connected to a positive electrode terminal plate (41). This crimped portion (17e) is welded to the positive electrode terminal plate (41) by applying high energy beams. The negative electrode side has a configuration similar to that of the positive electrode side. The contact area between the positive electrode terminal plate (41) and the crimped portion (17e) of the positive electrode external terminal (17) is set smaller than the corresponding contact area on the negative electrode side, and the volume of the crimped portion of the positive electrode external terminal is set larger than that of the corresponding crimped portion on the negative electrode side.