<p>Disclosed is an organic thin film solar cell which is characterized by comprising: a pair of electrodes which are arranged at a distance from each other, and at least one of which transmits light; and a bulk heterojunction type photoelectric conversion layer which is arranged between the electrodes and contains a p-type organic semiconductor and an n-type organic semiconductor. The organic thin film solar cell is also characterized in that the n-type organic semiconductor contains 0.1-80% by weight of fullerene C70 with the balance made up of a fullerene derivative.</p>
