RECTANGULAR SECONDARY BATTERY

A 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.