<p>PURPOSE: A composite layer is provided to easily prevent a short circuit between electrodes by thickening a hole generating layer. CONSTITUTION: A hole generating layer(111) includes a first region(111a) and a second region(111b). The first region and the second region respectively include a metal oxide and a compound which provides electron donating properties with respect to the metal oxide. The concentration of the metal oxide in the first region is higher than the metal oxide in the second region. The first region and the second region are alternatively and repetitively provided.</p>
