PURPOSE: To release automatic control at need as well as to make yet more stable running securable, by controlling a high gear clutch to be held in a released state at a time when a driver operates a switch device and inputs a command for direct-coupling prohibition.
CONSTITUTION: A high gear clutch is installed in a torque converter of an automatic transmission, and this high gear clutch is automatically controlled according to the driving state of an automobile. In the above-mentioned device, there is provided with a switch device for a direct coupling prohibiting command, to be operated by a driver, in addition. And, when there is command input for a direct coupling prohibition in this switch device, there is additionally provided with a controlling device holding the high gear clutch to be in a released state. With this constitution, lockup and unlock of the high gear clutch are automatically controlled according to the car's driving state, while this automatic control is released at need and fixed to an unlock state.