A transmission apparatus includes at least an auxiliary transmission for supplementing a main transmission. The auxiliary transmission includes a damper which has a damper characteristic adapted to a low speed select state of the auxiliary transmission, and which is disposed in a low speed transmission path used for transmission of torque in the low speed select state of the auxiliary transmission. The auxiliary transmission further comprises a bypass member defining a bypass transmission path bypassing the low speed damper. The bypass transmission path is a torque path used for transmission of torque in a high speed select state of the auxiliary transmission.