A driving device is a driving device driving a door that includes an upper door and a lower door rotatably connected to the upper door, and includes: a driving portion that is provided at a position spaced apart from a connecting portion rotatably connecting the upper door and the lower door and generates a driving force for driving the upper door or the lower door; and an adjusting portion that changes a degree of folding of the lower door with respect to the upper door based on the driving force. Such a driving device can enhance the degree of freedom in designing a door.