ELECTRIC POWER UNIT

PROBLEM TO BE SOLVED: To provide an electric power unit comprising an electric motor supported to a transmission case, and a power transmission disposed between an axle of a drive wheel supported by the transmission case and the electric motor and stored in the transmission case and being mounted on a vehicle, and to secure reduction ratio at large level by switching shift stage of a planetary gear mechanism by a speed change clutch, and to prevent size increasing in a vehicle width direction.SOLUTION: The electric power unit comprises: a transmission shaft 33 in which a power transmission 32A is disposed coaxially to an electric motor 31 for transmitting rotation power transmitted from the electric motor 31; an intermediate shaft 34 disposed between the transmission shaft 33 and an axle 13 in a vehicle longitudinal direction; a planetary gear mechanism 35 disposed coaxially to the intermediate shaft 34; and a speed change clutch 36 disposed coaxially to the transmission shaft 33 for switching shift stage of the planetary gear mechanism 35.