To obtain a detecting apparatus by which the solar direction can be detected in a wide visual-field range, by a method wherein sensor parts which correspond respectively to the positive direction and the negative direction of a prescribed axis are arranged in such a way that they are reversed by a specific angle at the upper part and the lower part.

For example, when sunlight is shone at a solar cell SL2, an electromotive force is generated. Then, when it is detected that the electromotive force is generated in the solar cell SL2, an angle θ can be found on the basis of the positional relationship between a hole 14 and the solar cell SL2. Since the number of solar cells to be installed side by side on the inner face of the curved part of a sensor part 2 is decided in advance, the angle θ can be found by an expression of θ=X(90/N), where X represents the subscript number of solar cells, e.g. 2 in the case of the solar cell SL2 and N represents the upper limit of the subscript number of the solar cells, i.e., 3 in the case of this example. The expression is computed by a signal processing part 7. As a result, the direction of the sun is found, and the value of the θ is outputted as a solar direction signal 13.