RECTANGULAR SECONDARY BATTERY

Provided is a highly-reliable rectangular secondary battery. This rectangular secondary battery is provided with: a rectangular exterior body having an opening, a bottom part, a first lateral wall, a second lateral wall, a third lateral wall, and a fourth lateral wall; a sealing plate for sealing the opening; and a flat wound electrode body obtained by winding a positive electrode plate and a negative electrode plate with a separator therebetween, wherein a plurality of the flat wound electrode bodies are arranged in the rectangular exterior body. The flat wound electrode bodies each have: a flat region formed at the center, a first bent region having a bent outer surface and being formed on one end side of the flat region; and a second bent region having a bent outer surface and being formed on the other end side of the flat region. A tape is attached to the outer surface of the first bent region. The plurality of flat wound electrode bodies are arranged such that each of the first bent regions is located on the first lateral wall side in an orientation in which the corresponding winding axis is perpendicular to the bottom part.