There is provided a shift control device for an automated manual transmission having power transmission lines equipped with respective start clutches and gears. The shift control device includes clutch actuation mechanisms and a transmission shift controller that causes the clutch actuation mechanisms to regulate the clutch engagement forces applied to the start clutches so as to perform clutch changeover upon gear selection for a desired gear range in response to a transmission shift command. Each of the clutch actuation mechanisms has primary and secondary clutch engagement force regulation units. The transmission shift controller outputs a control signal to the primary and secondary clutch engagement force regulation units of each clutch actuation mechanism under the clutch changeover control so that either the primary or secondary clutch engagement force regulation unit of each clutch actuation mechanism operates to regulate a corresponding one of the clutch engagement forces according to the control signal.