An electronic instrument has a power unit configured to allow insertion of a cell and to supply an electric power output from the inserted cell, a charging unit configured to charge the cell inserted in the power unit, and a voltage detecting unit configured to detect a voltage value of the cell inserted in the power unit. A cell type determining unit is configured to determine that the cell inserted in the power unit is a secondary cell as a rechargeable battery when the voltage value detected by the voltage detecting unit is a value equal to or lower than a predetermined threshold value and to determine that the cell inserted in the power unit is a primary cell as a non-rechargeable battery when the voltage value detected by the voltage detecting unit is larger than the predetermined threshold value.