To provide a power plant which makes it possible to make the power plant more compact in size, reduce manufacturing costs thereof, and improve the degree of freedom in design. The power plant 1 comprises an engine 3, and first and second rotating machines 10 and 20, and drives front wheels 4 by motive power from these. The first rotating machine 10 includes first and second rotors 14 and 15, and a stator 16, and is configured such that a ratio between the number of armature magnetic poles generated in the stator 16, the number of magnetic poles of the first rotor 14, and the number of soft magnetic material cores 15a of the second rotor 15 becomes 1:m:(1+m)/2 (m≠1.0).