A developer collecting device includes a housing provided with an opening opposed to a developer carrying member, a collecting member provided on a support member and capable of coming into contact with and separating from the developer carrying member, a suction path provided between the opening and a suction member for sucking developer removed from the developer carrying member, an opening-closing plate that opens or closes the suction path, an urging member that urges the opening-closing plate, a retaining member that retains the opening-closing plate, and an opening-closing unit including a rotating member and an elastic member whose ends are connected to the rotating member and the support member. The elastic member is pulled so as to rotate the rotating member in association with a movement of the collecting member, thereby rotating the opening-closing plate so as to open or close the suction path.