This paper is a summary of the applications of the solar cell to automobiles. The solar cell, which generates electric power using solar energy, has become more efficient for electric power generation. As the result, a higher electric power output has been able to be obtained with a smaller cell.Therefore, for internal combustion engine powered vehicles, the solar cell is being applied to an auxiliary charger for prevention of battery-running-down, to a ventilation system, etc.. However, the ultimate application of the solar cell is for the vehicle power source. One application is for the auxiliary battery charging of electric vehicles and the other is for solar powered vehicles for which solar energy itself is utilized as the power source.We made several solar powered vehicles as an experiment using silicon cells (which are the most popular type of solar cell) applied to conventional techniques used in electric vehicles. One of them ran the whole distance in the Pentax World Solar Challenge Race held in Australia in 1987. The technique may be practically applied to commuter cars and will be useful for improving the performance of electric vehicles.