To attain increase in the power generation output of a power generator, by suppressing the generation of noise, without generating the problem regarding its lifetime.

The generator 2 of the power generation apparatus 1 includes a first rotor 9 for supporting a magnet 8 rotatively about an axial center 7, and a second rotor 11 rotatively about the axial center 7, to support a power-generating coil 10 facing the magnet 8. The engine 3 has a first engine 27 for rotatively driving the first rotor 9 in one direction A about the axial center 7 and a second engine 28 for rotatively driving the second rotor 11, in a direction B opposite to the one direction A about the axial center 7. The power generator also includes first, second starters 29, 30 which can start the first, second engines 27, 28. The power generator also includes at least either one one-way clutch of a first one-way clutch 31, for allowing the first rotor 9 to allow rotation only in one direction A and a second one-way clutch 32 allowing rotation, in only the opposite direction B of the second rotor 11.