NOVELTY - The solar cell (1) has photonic crystal which is formed inside photoelectric converting layer (2). The quality factor (Q) value representing the size of resonance effect due to the coupling of crystal and external field is proportional to the reciprocal number of coefficient indicating coupling intensity of crystal and field. The Q value representing size of resonance effect due to medium of layer is proportional to reciprocal number of absorption coefficient of light. Both the Q values exist in a specific range when predetermined condition is satisfied.    USE - Solar cell of solar cell panel, for use as power supply in apparatus (both claimed) such as portable or non-portable electronic device, domestic electrical appliance, advertising sign or vehicle.    ADVANTAGE - The photonic crystal is formed inside the photoelectric converting layer such that Q value representing the size of resonance effect due to the coupling of photonic crystal and external field and other Q value representing the size of resonance effect due to the medium of photoelectric converting layer exist in a certain range when predetermined conditions are satisfied so that the absorption effect of light by photonic crystal is increased while improving the absorption factor of light of solar cell. The photonic crystal is formed in both the front and back surfaces of photoelectric converting layer so that the electric power generation efficiency of solar cell can be improved. The metal electrode layer reflects the light which passed through the photoelectric converting layer so as to return the light to the photoelectric converting layer so that the photoelectric conversion rate can be improved. The manufacturing process of solar cell can be simplified. The columnar medium formed in the photoelectric conversion layer is smaller than the height of photoelectric conversion layer so that the photonic crystal can be formed easily.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) solar cell panel; and    (2) apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of solar cell.    Solar cell (1)    Photoelectric converting layer (2)    Metal layer (6)    N-type semiconductor layer (22)    Defect (31)