A dust bag includes a frame disposed inside the bag main body. The frame includes at least one non-flexible portion extending in the first direction and/or a second direction perpendicular to the first direction so as not to have flexibility in the first direction, and at least one flexible portion coupled with the at least one non-flexible portion and extending in an intersection direction intersecting with the first direction and the second direction so as to have flexibility in the first direction. The frame is configured to be extensible and compressive in the first direction due to the at least one flexible portion deflected when an external force is applied in the first direction. A total width of the at least one flexible portion in the first direction is equal to or wider than a total width of the at least one non-flexible portion in the first direction.