A transmission is provided which has a very compact system configuration and is capable of exerting high energy efficiency over all speed regions from a low speed region to a high speed region, while providing improved operability free from a torque shortage. To this end, the transmission has an input shaft 3, an intermediate output shaft 8, a planetary gear mechanism 9, a first pump-motor 7, and a second pump-motor 15 connected to the first pump-motor 7, the input shaft 3 being coupled to a first element (planetary carrier 12) of the planetary gear mechanism 9, the second pump-motor 15 being coupled to a second element (sun gear 19) of the planetary gear mechanism 9, the intermediate output shaft 8 being coupled to a third element (ring gear 16) of the planetary gear mechanism 9, and the transmission further comprising a switching mechanism (synchromesh mechanism 6) for selectively coupling the first pump-motor 7 to either the input shaft 3 or the intermediate output shaft 8.