The present invention is to prevent an absorption member from dropping off while reducing damage to the absorption member. An absorption rotor includes plural spokes extending in a radial manner from the circumference of the rotation axis, a tubular rim 4 coupling end portions of the plural spokes, an absorption member accommodated in a space which is surrounded by the plural spokes and the rim, the absorption member that absorbs a substance to be absorbed when a gas passes through, and a drop-off prevention member respectively fixed to the spoke and the absorption member, the drop-off prevention member that prevents the absorption member from dropping off the spoke. The drop-off prevention member is arranged between the absorption member and the spoke, and between a surface from which the gas flows into the absorption member and a surface from which the gas flows out of the absorption member.