On an input shaft are provided in order from a side of an engine a torque converter with a lock-up clutch, a first planetary gear set as a multiplying mechanism, a counter drive gear outputting a rotational drive force to a countershaft, a second planetary gear set as a speed-change element, a third planetary gear set as a speed-change element. Accordingly, there can be provided an automatic transmission for six forward speeds with plural planetary gear sets, clutches and brakes that can properly reduce a clutch capacity and restrain gear noises with its compact and light-weighted structure.