To dispense with installation of a rotating device for rotating a supply member separately from the rotating device stated below when toner supplied from a cylindrical toner storage container to a toner hopper by rotation of the toner storage container by the rotating device is replenished to a developing device by rotation of the supply member disposed in the toner hopper.

In the toner replenishing device 10, at least a part of the cylindrical toner storage container 110 is rotated by the rotating device 130, and the toner stored in the toner storage container is supplied to the toner hopper 120, and the supply member 122 disposed in the toner hopper is rotated to replenish the toner to the developing device 4. The toner replenishing device 10 includes a rotation transmission mechanism 140 for transmitting the rotation of the toner storage container to the supply member disposed in the toner hopper.