A battery which can be assembled by using reduced man-hours. The battery has a battery cell having a positive electrode terminal and a negative electrode terminal which are arranged on one side surface of the battery cell, a circuit board placed facing the one side surface of the battery cell and having a first board terminal and a second board terminal, a first conduction member for conducting the positive electrode terminal and first board terminal to each other, a second conductive member for conducting the negative electrode terminal and the second board terminal to each other, a first cover placed between the circuit board and the battery cell, a second cover placed facing the first cover with the circuit board sandwiched between the first and second covers, a connection section for connecting the first and second covers to each other, and a cover for covering the circuit board. The circuit board is mounted to the one side surface of the battery cell while being sandwiched between the first and second covers.