When an automatic transmission is in a manual mode, a transmission ECU calculates a speed sftrng manually requested by the driver and a speed sftrngmap set by a shift map and then performs a shift prohibition procedure. In this procedure, if the engine coolant temperature is equal to or lower than a predetermined coolant temperature or the AT fluid temperature is equal to or lower than a predetermined fluid temperature, a prohibition, determination flag xthlow is set to “on”, and if the engine coolant temperature is higher than the predetermined coolant temperature and the AT fluid temperature is higher than the predetermined fluid temperature, the prohibition determination flag xthlow is set to “off”. When the prohibitions determination flag xthlow is “on”, the speed sftrngmap is set as the upper limit of the speed sftrng.