To reduce the possibility of the lowering of the durability of the one-way clutch OWC of an automatic transmission.

A part of transmission gears is registered to be an OWC operation gear as a transmission gear formed by operating OWCF1 and F2 and in which when a load of a specified value or higher is inputted from a road surface, a load exceeding a specified value may be applied to the OWC. An other part of the transmission gear is registered to be an OWC non-operation gear as a transmission gear formed without operating OWCFO and F1 and F2 or a transmission gear formed by operating the OWCFO and in which when a load of a specified value or higher is inputted from the load surface, a load exceeding a specified value may be applied to the OWC. The device is controlled so that, when it is estimated that the load exceeding the specified value is inputted from the road surface, the transmission gear is brought into a non-operation gear for the OWC.