PURPOSE: To prevent a sealing member from being easily peeled off by vibration, etc., by forming the adhesive surface of the peeling start end of the sealing member for sealing an opening part in a chevron shape and sticking a seal turn-up part with one side of the chevron shape as a turn-up line at the time of transporting a cartridge.

CONSTITUTION: As to the cartridge 1, the sealing member 4 for sealing the opening part 3 s turned up along the one side (a) of the adhesive surfaces (a) and (b) in the chevron shape on a seal peeling start end side to form and stick the turn-up part 5. Therefore, adhesive force which sufficiently resists to load caused by frictinal force at the time of transporting the cartridge is obtained and the member 4 is prevented from being easily peeled off. In the case of replenishing the developer, the member 4 is easily peeled off from a top part without peeling resistance by releasing the stick of the turn-up part 5 and pulling the turn-up part 5 with the top part of the chevron shape of the adhesive surfaces (a) and (b) as an origin.