PURPOSE: To smooth upshift at the time of coasting by prohibiting the use of a coasting frictional engagement device in a low gear side shift step of upshift when a shift range is laid within an upshift permitting range.

CONSTITUTION: A coasting frictional engagement device judging means first judges whether the shift range detected by a detecting means is within a range permitting the execution of upshift in the state where the coasting frictional engagement device is used, or not. When the shift range is judged within the upshift permitting range, the use of the coasting frictional engagement device is prohibited in a low gear side shift step of upshift. Thus, even if the upshift is executed as it remains in coasting state, the transmitting direction of power is never changed in shifting transient time, and the upshift at the time of coasting can be smoothly realized.