To provide an automated manual transmission for a vehicle, configured to prevent reduction in torque generated during gear shifting to eliminate discomfort during gear shifting.

An automated manual transmission comprises a speed change part equipped with a plurality of shifting mechanisms to generate different gear ratios between an input shaft and an output shaft, and a continuously variable transmitting mechanism installed between the output shaft and a power providing device to provide a power to the input shaft of the speed change part and arranged to transmit the power received from the power providing device to the output shaft with continuously variable gear ratio. The continuously variable transmitting mechanism has a driving disc, a driven disc, a movable ball arranged so that its contact radius with the driving disk and the contact radius with the driven disk are changed mutually simultaneously, and a movable ball regulating device to move the movable ball.