The present invention provides a cartridge detachably mountable to a main body of an image forming apparatus, comprising a developing frame, a developer carrying member provided in the developer frame and adapted to hold and carry developer, a developer containing container for containing the developer and for supplying the developer to the developer frame, a seal member for unsealably sealing an opening portion through which the developer is supplied from the developer containing container to the developing frame, a rotary member for supplying the developer toward the developer carrying member, a first drive transmitting device for effecting drive transmission between the developer carrying member and the rotary member, and a second drive transmitting device for transmitting the driving to the seal member to unseal the seal member, and wherein at least a part of the first drive transmitting device is provided at one end of the developer carrying member in a longitudinal direction thereof and the second drive transmitting device is provided at the other end of the developer carrying member in the longitudinal direction, and drive transmission between the one end and the other end is effected by the developer carrying member or the rotary member.