Opening/closing device

A device for opening and closing comprising:

• a body that performs a closing operation in an opening-closing direction and that is configured to be a partition between at least two areas;
• a roller member that protrudes from the body in an extending direction of the body that is perpendicular to the opening-closing direction, the roller member being rotatably supported by the body;
• a guide rail that includes a receiving surface, the receiving surface receives and contacts the roller member at a side of the roller member provided away from a center of the roller member in a body thickness direction that is perpendicular to the extending direction of the body and to the opening-closing direction, and the receiving surface is configured to guide the roller member along a guide path;
• a support member that includes:
• a support piece that opposes the body in the extending direction of the body and that is continuous along the opening-closing direction, the support piece having a portion that is connected to a portion of the guide rail;
• and
• a cover piece that opposes a backside of the receiving surface in the body thickness direction and that is continuous along the opening-closing direction;
• a first engaged part that is fixed to the support piece and includes a protruding piece that protrudes in the body thickness direction from the backside of the receiving surface towards the cover piece, the protruding piece extending from the backside of the receiving surface;
• and
• a close prevention device that is provided integrally with the body, the close prevention device including a brake engage part that is configured to attach to and detach from the protruding piece so as to brake the closing operation of the body, wherein
• both the protruding piece and the brake engage part are disposed in a space at least defined by the backside of the receiving surface, the support piece, the cover piece and an end face of the body that opposes the support piece and that extends along the body thickness direction, the space being continuous along the guide path.