A fiber arranging device comprising: first guides for guiding a first feeding of first tapes in a first feeding direction, the first tapes being first fibers or prepregs; a first moving mechanism configured to change an interval between the first guides, for the first feeding of the first tapes with a first interval; second guides for guiding a second feeding of second tapes in a second feeding direction, the second tapes being second fibers or prepregs, the second feeding direction differing from the first feeding direction; a second moving mechanism configured to change an interval between the second guides, for the second feeding of the second tapes with a second interval; and a roller for feeding, in a same feeding direction, the first tapes fed with the first interval from the first guides and the second tapes fed with the second interval from the second guides, the roller disposing the first tapes and the second tapes alternately, wherein the first moving mechanism includes: at least one rotating body having portions of which outer diameters are different from each other, the at least one rotating body rotating around a common rotation axis; and power transmission members for respectively moving the first guides by moving amounts different from each other, the moving amounts corresponding to the outer diameters, the power transmission members each being a closed curved line shaped, the power transmission members moving in length directions by receiving power from the portions of the at least one rotating body respectively, the power transmission members being singly coupled to the first guides. first guides for guiding a first feeding of first tapes in a first feeding direction, the first tapes being first fibers or prepregs; a first moving mechanism configured to change an interval between the first guides, for the first feeding of the first tapes with a first interval; second guides for guiding a second feeding of second tapes in a second feeding direction, the second tapes being second fibers or prepregs, the second feeding direction differing from the first feeding direction; a second moving mechanism configured to change an interval between the second guides, for the second feeding of the second tapes with a second interval; and a roller for feeding, in a same feeding direction, the first tapes fed with the first interval from the first guides and the second tapes fed with the second interval from the second guides, the roller disposing the first tapes and the second tapes alternately, wherein the first moving mechanism includes: at least one rotating body having portions of which outer diameters are different from each other, the at least one rotating body rotating around a common rotation axis; and power transmission members for respectively moving the first guides by moving amounts different from each other, the moving amounts corresponding to the outer diameters, the power transmission members each being a closed curved line shaped, the power transmission members moving in length directions by receiving power from the portions of the at least one rotating body respectively, the power transmission members being singly coupled to the first guides. at least one rotating body having portions of which outer diameters are different from each other, the at least one rotating body rotating around a common rotation axis; and power transmission members for respectively moving the first guides by moving amounts different from each other, the moving amounts corresponding to the outer diameters, the power transmission members each being a closed curved line shaped, the power transmission members moving in length directions by receiving power from the portions of the at least one rotating body respectively, the power transmission members being singly coupled to the first guides.