The invention relates to a controller enabling a reduction in the size of a driving device having a differential mechanism and a stepped transmission, an improvement in fuel economy, and the suppression of gear shift shock when the stepped transmission is shifted. 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 such 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 NE is freely set by a hybrid control means (52). Unlike the non-continuously variable transmission state of the differential part (11) directly affected by the tieup, the engine speed NE is prevented from lowering to suppress a shock in shifting.