A charging control device configured to use an in-vehicle solar cell for installation in a vehicle; the vehicle comprising: a motor generator (13, 14) configured to generate a driving force and to generate regenerative electric power; and a main battery electrically connected to the motor generator (13, 14), the main battery being configured to supply electric power to the motor generator (13, 14) and to store the regenerative electric power; the vehicle being capable of traveling using at least the driving force generated by the motor generator (13, 14), characterized in that the vehicle comprises: a sub-battery configured to supply electric power to various accessory devices mounted on the vehicle, and in that the charging control device comprises: traveling determination means for determining whether or not the vehicle is traveling, an electric power supply unit comprising the in-vehicle solar cell, which is configured to supply electric power generated by the in-vehicle solar cell to the main battery and the sub-battery; and a charging control unit configured to control charging of the main battery and the sub-battery using the electric power generated by the in-vehicle solar cell and supplied from the electric power supply unit, the charging control unit being configured to: when the traveling determination means determines that the vehicle is traveling, prevent the electric power generated by the in-vehicle solar cell from being supplied from the electric power supply unit to the main battery and supply the electric power generated by the in-vehicle solar cell from the electric power supply unit to the sub-battery. the vehicle comprising: a motor generator (13, 14) configured to generate a driving force and to generate regenerative electric power; and a main battery electrically connected to the motor generator (13, 14), the main battery being configured to supply electric power to the motor generator (13, 14) and to store the regenerative electric power; a motor generator (13, 14) configured to generate a driving force and to generate regenerative electric power; and a main battery electrically connected to the motor generator (13, 14), the main battery being configured to supply electric power to the motor generator (13, 14) and to store the regenerative electric power; the vehicle being capable of traveling using at least the driving force generated by the motor generator (13, 14), characterized in that the vehicle comprises: a sub-battery configured to supply electric power to various accessory devices mounted on the vehicle, and in that the charging control device comprises: traveling determination means for determining whether or not the vehicle is traveling, an electric power supply unit comprising the in-vehicle solar cell, which is configured to supply electric power generated by the in-vehicle solar cell to the main battery and the sub-battery; and a charging control unit configured to control charging of the main battery and the sub-battery using the electric power generated by the in-vehicle solar cell and supplied from the electric power supply unit, the charging control unit being configured to: when the traveling determination means determines that the vehicle is traveling, prevent the electric power generated by the in-vehicle solar cell from being supplied from the electric power supply unit to the main battery and supply the electric power generated by the in-vehicle solar cell from the electric power supply unit to the sub-battery. traveling determination means for determining whether or not the vehicle is traveling, an electric power supply unit comprising the in-vehicle solar cell, which is configured to supply electric power generated by the in-vehicle solar cell to the main battery and the sub-battery; and a charging control unit configured to control charging of the main battery and the sub-battery using the electric power generated by the in-vehicle solar cell and supplied from the electric power supply unit, the charging control unit being configured to: when the traveling determination means determines that the vehicle is traveling, prevent the electric power generated by the in-vehicle solar cell from being supplied from the electric power supply unit to the main battery and supply the electric power generated by the in-vehicle solar cell from the electric power supply unit to the sub-battery.