Gear transmission with a control device

A control device for giving an existing gear type transmission a parking lock function to lock a vehicle; a control method thereof; and an automobile having an improved transmission. The gear type transmission comprises a gear type speed change mechanism (5) provided with a mesh type clutch (3), and a second friction clutch (4) installed between the shafts of the speed change mechanism to enable torque transfer during shifting. A parking demand detecting means (9) detects the driver's parking demand. And, when it detects the driver's parking demand, a control device (10) sends an instruction signal to an actuator to instruct the latter to engage both the mesh type clutch (3) and the second friction clutch (4).