In a planetary gear unit 12 of a power transmitting device 10, a sun gear S1 is connected to an electric motor 20, a carrier CA1 is non-rotatably fixed to a case 40, and a ring gear R1 is connected to an output gear 13 and an oil pump 30. As a result, a structure of carrier being fixed/output power being taken out via ring gear is obtained. Therefore, for example, a structure can be employed in which the ring gear and the output gear are integrated. Accordingly, as compared with a structure in which a ring gear is fixed/output power is taken out via carrier and the output gear has to be axially offset and connected to a carrier, an axial space can be omitted, to allow the power transmitting device to be downsized.