In a power transmitting device, a discharge port (104) of an electromagnetic pump (100) is connected through a switching valve (70) to an oil path (48) of a clutch (C1) and to a lubricating oil path (68). While an engine is being operated below a predetermined rotational speed, an operating oil is supplied from the electromagnetic pump (100) to the lubricating oil path (68), and while the engine is in an automatically stopped state, hydraulic pressure is applied from the electromagnetic valve (100), instead of from a linear solenoid (SLC1), to the clutch (C1) for vehicle starting purposes. The above configuration can reduce a load on a mechanical oil pump (42), and as a result, the entire device can be reduced in size. Also, allowing the hydraulic pressure to be always applied to the clutch (C1) while the engine is in an automatically stopped state enables the clutch (C1) to be quickly engaged by the linear solenoid (SLC1) immediately after the engine is automatically started next time, and this allows the vehicle to be smoothly started.