Construction capable of improving the convenience of an electric automobile is achieved by making the drive apparatus for an electric automobile in which a planetary-gear transmission 11 is assembled more compact and simple, and increasing the distance traveled per charge. The planetary-gear transmission 11 comprises a single-pinion first planetary-gear mechanism 12 and a double-pinion second planetary-gear mechanism 13, and reduces power from an electric motor 1a by a desired reduction ratio before transmitting that power to a driven-side rotating shaft 5a. A first braking device 14 switches a ring gear 22 and a second braking device 15 switches a second sun gear 19 between a state of being allowed to rotate and a state of being prevented from rotating with respect to a fixed portion.