A developer accommodating unit comprising: a developer accommodating member, provided with an opening for permitting discharge of developer, for accommodating the developer; a sealing member including a connecting portion for being connected to said developer accommodating member so as to seal the opening, the connecting portion including an early unsealed connecting portion and a late unsealed connecting portion, the early unsealed connecting portion and the late unsealed connecting portion extending in a longitudinal direction of the connecting portion, the early unsealed connecting portion and the late unsealed connecting portion being disposed such that the early unsealed connecting portion opposes the late unsealed connecting portion via the opening; and an unsealing member for exposing the opening by peeling said connecting portion from said developer accommodating member in an unsealing direction crossing the longitudinal direction, said unsealing member being configured to be rotated such that the early unsealed connecting portion is peeled before the late unsealed connecting portion, wherein said early unsealed connecting portion includes a first connecting portion and a second connecting portion with respect to the longitudinal direction, and characterized in that said first connecting portion is located at a position where an end portion of the unsealing member is located and said second connecting portion is located at a position where a central portion of the unsealing member is located, with respect to a rotational axis direction of the unsealing member, and said unsealing member is flexible so that, when said connecting portion is peeled from said developer accommodating member, said unsealing member is flexed in a larger flexure amount at the central portion than at the end portion so that said first connecting portion is peeled before said second connecting portion. a developer accommodating member, provided with an opening for permitting discharge of developer, for accommodating the developer; a sealing member including a connecting portion for being connected to said developer accommodating member so as to seal the opening, the connecting portion including an early unsealed connecting portion and a late unsealed connecting portion, the early unsealed connecting portion and the late unsealed connecting portion extending in a longitudinal direction of the connecting portion, the early unsealed connecting portion and the late unsealed connecting portion being disposed such that the early unsealed connecting portion opposes the late unsealed connecting portion via the opening; and an unsealing member for exposing the opening by peeling said connecting portion from said developer accommodating member in an unsealing direction crossing the longitudinal direction, said unsealing member being configured to be rotated such that the early unsealed connecting portion is peeled before the late unsealed connecting portion, wherein said early unsealed connecting portion includes a first connecting portion and a second connecting portion with respect to the longitudinal direction, and characterized in that said first connecting portion is located at a position where an end portion of the unsealing member is located and said second connecting portion is located at a position where a central portion of the unsealing member is located, with respect to a rotational axis direction of the unsealing member, and said unsealing member is flexible so that, when said connecting portion is peeled from said developer accommodating member, said unsealing member is flexed in a larger flexure amount at the central portion than at the end portion so that said first connecting portion is peeled before said second connecting portion.