A hybrid driving unit in which a first electric motor (20), a second electric motor (23), a transmission (22) and a power splitting planetary gear (21) are disposed in order from the front side (the side of an internal combustion engine) on an axis within a casing member (14). Since the first electric motor (20) and the second electric motor (23) are disposed adjacently to each other, partial cases for storing these first and second electric motors (20) and (23) may be combined, thus facilitating the accommodation for producing the unit in series.