Battery and Portable Electronic Apparatus

A battery which can be assembled by using reduced man-hours. The battery has a battery cell (20) having a positive electrode terminal (21) and a negative electrode terminal (22) which are arranged on one side surface of the battery cell, a circuit board (30) placed facing the one side surface of the battery cell (20) and having a first board terminal (30a) and a second board terminal (30b), a first conduction member (31) for conducting the positive electrode terminal (21) and first board terminal (30a) to each other, a second conductive member (32) for conducting the negative electrode terminal (22) and the second board terminal (30b) to each other, a first cover (41) placed between the circuit board (30) and the battery cell (20), a second cover (42) placed facing the first cover (41) with the circuit board (30) sandwiched between the first and second covers (41, 42), a connection section (43) for connecting the first and second covers (41, 42) to each other, and a cover (40) for covering the circuit board (30). The circuit board (30) is mounted to the one side surface of the battery cell (20) while being sandwiched between the first and second covers (41, 42).