The twin clutch-type transmission can include a hydraulic twin clutch including the first clutch and the second clutch disposed on main shafts. The shift change controlling apparatus is configured to control shift change operation to and adjacent speed change stage by alternately changing an engagement state of the first clutch and the second clutch. The shift change controlling apparatus can also execute a pre-shift change of supplying a pre-pressure on one of the first and second clutches, while another of the first and second clutches is engaged. The pre-pressure provides a pre-engagement of the unengaged clutch. First and second clutch actuators are configured to actuate the first and second clutches, respectively. When the pre-shift change is executed, the pre-pressure is applied for a predetermined period and then removed prior to a driving of a shift gear or actuating a shift change.