A vehicle comprising: a power unit including a transmission configured to change the speed of rotation produced by output power of a drive source (E, M) for travel and a case accommodating the transmission, the transmission being located behind a crankcase of the drive source in the front-rear direction of the vehicle and including an input shaft that receives power transmitted from a crankshaft, an output shaft that outputs power of the transmission to the outside of the transmission, a gear train located on a power transmission route between the input and output shafts and to change the speed of rotation produced by power transmitted from the input shaft to the output shaft, and a pivotally supported change shaft, the change shaft being angularly movable about an axis to change a gear ratio of the transmission; and an operation unit configured to angularly move the change shaft, the operation unit including an electric motor and a power transmission structure configured to transmit power of the electric motor to the change shaft in the form of rotational power by which the change shaft is angularly moved, wherein the operation unit is mounted on an exterior of the case, characterized in that: the operation unit is aligned with the crankcase in the front-rear direction of the vehicle and located across the input shaft from the crankcase in the front-rear direction of the vehicle and located behind the change shaft, a rear end of the case is located above the output shaft, a front end of the operation unit is located ahead of the rear end of the case, a lower end of the operation unit is located below a rear lower end of the case, and points at which the operation unit is fastened to the case are located above an upper end of an oil pan. a power unit including a transmission configured to change the speed of rotation produced by output power of a drive source (E, M) for travel and a case accommodating the transmission, the transmission being located behind a crankcase of the drive source in the front-rear direction of the vehicle and including an input shaft that receives power transmitted from a crankshaft, an output shaft that outputs power of the transmission to the outside of the transmission, a gear train located on a power transmission route between the input and output shafts and to change the speed of rotation produced by power transmitted from the input shaft to the output shaft, and a pivotally supported change shaft, the change shaft being angularly movable about an axis to change a gear ratio of the transmission; and an operation unit configured to angularly move the change shaft, the operation unit including an electric motor and a power transmission structure configured to transmit power of the electric motor to the change shaft in the form of rotational power by which the change shaft is angularly moved, wherein the operation unit is mounted on an exterior of the case, characterized in that: the operation unit is aligned with the crankcase in the front-rear direction of the vehicle and located across the input shaft from the crankcase in the front-rear direction of the vehicle and located behind the change shaft, a rear end of the case is located above the output shaft, a front end of the operation unit is located ahead of the rear end of the case, a lower end of the operation unit is located below a rear lower end of the case, and points at which the operation unit is fastened to the case are located above an upper end of an oil pan. the operation unit is aligned with the crankcase in the front-rear direction of the vehicle and located across the input shaft from the crankcase in the front-rear direction of the vehicle and located behind the change shaft, a rear end of the case is located above the output shaft, a front end of the operation unit is located ahead of the rear end of the case, a lower end of the operation unit is located below a rear lower end of the case, and points at which the operation unit is fastened to the case are located above an upper end of an oil pan.