PROBLEM TO BE SOLVED: To provide a controller enabling reduction in the size of a driving device having a differential mechanism and a stepped transmission, improvement in fuel economy, and suppression of gear shift shock, when the stepped transmission is shifted. SOLUTION: The driving device comprises a selector clutch C0 or a selector brake B0, and accordingly, a transmission mechanism 10 can be switched between a continuously variable transmission state and a stepped transmission state to provide concurrently both advantages as the fuel economy improvement effect of the transmission electrically changed in gear ratio and the high transmission efficiency of a gear type transmission device which mechanically transmits power to the driving device. Furthermore, when the clutch-to-clutch shifting of an automatic transmission part 20 is performed in a tied-up state, a differential part 11 is brought into the continuously variable transmission state by a switchingly control means 50, and an engine speed N E is set freely by a hybrid control means 52. Unlike the non-continuously variable transmission state of the differential part 11 that is affected directly by the tieup, the engine speed N E is prevented from lowering to suppress shocks in shifting. COPYRIGHT: (C)2007,JPO&INPIT