An automatic transmission for an automotive vehicle comprises electromagnetic valves 5A-5C activated or deactivated in accordance with a given shift schedule determined based on traveling conditions of the automotive vehicle, a plurality of planetary gear trains 4A-4C driven by an output force of an engine, a plurality of friction devices B1-B4 and C1-C3 receiving hydraulic pressure to selectively connect or fix components constituting planetary gear trains 4A-4C, and a mechanical shift valve 6A having a pair of pressure chambers 62A and 63A and plural ports 64A, 65A and 66A. Upon application of hydraulic pressure to pressure chamber 62A, a fluid communicating path is established in the shift valve 6A so as to connect brake B1 and manual shift valve 8. When hydraulic pressure is applied to both of pressure chambers 62A and 63A, pressurized oil is drained from brake B1. Supply and release of hydraulic pressure to clutches C1-C3, brakes B1-B4 and pressure chambers 62A and 63A of the mechanical shift valve 6A is controlled by electromagnetic valves 5A-5C.