A battery module comprising: a plurality of battery holders, each of which includes an accommodation section; a plurality of rechargeable batteries that is accommodated in the respective accommodation section and arranged side by side; a metal plate member located at least between ones of the rechargeable batteries that are adjacent to each other in an arrangement direction; a pressure application member (B, N, 14, 15) that applies pressure to the rechargeable batteries and the plate member in the arrangement direction of the rechargeable batteries; and planar end plates (14, 15) are arranged at opposite ends of the battery module in the arrangement direction of the rechargeable batteries, wherein each battery holder includes a plate holding section having an opening into which the plate member is fitted, the plate member is fitted into the opening such that the plate member protrudes from an associated one of the battery holders in the arrangement direction of the rechargeable batteries, and characterized in that at least a part of the plate member is thicker than the plate holding section in the arrangement direction of the rechargeable batteries, and the plate member is arranged in the opening of the plate holding section without overlapping with the battery holder as viewed in the arrangement direction of the rechargeable batteries. a plurality of battery holders, each of which includes an accommodation section; a plurality of rechargeable batteries that is accommodated in the respective accommodation section and arranged side by side; a plurality of rechargeable batteries that is accommodated in the respective accommodation section and arranged side by side; a metal plate member located at least between ones of the rechargeable batteries that are adjacent to each other in an arrangement direction; a pressure application member (B, N, 14, 15) that applies pressure to the rechargeable batteries and the plate member in the arrangement direction of the rechargeable batteries; and planar end plates (14, 15) are arranged at opposite ends of the battery module in the arrangement direction of the rechargeable batteries, wherein each battery holder includes a plate holding section having an opening into which the plate member is fitted, the plate member is fitted into the opening such that the plate member protrudes from an associated one of the battery holders in the arrangement direction of the rechargeable batteries, and characterized in that at least a part of the plate member is thicker than the plate holding section in the arrangement direction of the rechargeable batteries, and a pressure application member (B, N, 14, 15) that applies pressure to the rechargeable batteries and the plate member in the arrangement direction of the rechargeable batteries; and planar end plates (14, 15) are arranged at opposite ends of the battery module in the arrangement direction of the rechargeable batteries, wherein each battery holder includes a plate holding section having an opening into which the plate member is fitted, the plate member is fitted into the opening such that the plate member protrudes from an associated one of the battery holders in the arrangement direction of the rechargeable batteries, and characterized in that at least a part of the plate member is thicker than the plate holding section in the arrangement direction of the rechargeable batteries, and the plate member is arranged in the opening of the plate holding section without overlapping with the battery holder as viewed in the arrangement direction of the rechargeable batteries.