An automated manual transmission for a vehicle may include an input shaft (INPUT) configured to allow a rotational force to be transmitted from a power source, an output shaft configured to be disposed in parallel with the input shaft so as to draw out power, and a plurality of shifting gear pairs including driving gears and driven gears installed on the input shaft and the output shaft respectively so as to be circumscribed in pairs and provide different shifting stages for respective pairs, wherein at least two of the shifting gear pairs are respectively configured so that one of the driving gear and the driven gear is connected to the input shaft or the output shaft so as to control power by planetary gearsets, and the other is connected to the input shaft or the output shaft so as to control power by a synchronizer.