An object of the present invention is to provide a natural energy extraction apparatus which can extract kinetic energies of river water currents or tidal water currents at various depth layers, and which is easy to attach to the fixed structure above water current. A natural energy extraction apparatus comprises a float, a vertical-axis water turbine fixed to the float and extending downward, a power transmission device engaging an upper end of the float and converting rotational kinetic energy of the float to driving torque for driven equipment, and arm members supporting the power transmission device rotatably around a horizontal axis at one ends and supported by a fixed structure above a water current rotatably around a horizontal axis at the other ends, wherein the float and the vertical-axis water turbine are located in a river water current or tidal water current.