To provide a supported flange for paper roll fixed on an end part of paper roll for supporting paper roll on a paper roll storing mechanism capable of storing different sizes of paper roll for making replacement of paper roll easy.

This supported flange 66 for paper roll is provided with a first disk shaped member 16 and a second disk shaped member 17 rotatable around a center axis common to the first disk shaped member 16 and including a hole 18 passing through a plate surface. A partially cylindrical member 23 projects out around the hole 18 of the second disk shaped member 17. The partially cylindrical member 23 is provided with a screw 67 projecting outward. A cylindrical member 12 projects out from the first disk shaped member 16 through the hole 18. A distance from the center axis to an inner surface of the partially cylindrical member 23 is longer than a distance from the center axis to the closest part of an outer surface of the cylindrical member 21 and is shorter than a distance from the center axis to the farthest part of the outer surface of the cylindrical member 21.