A damper includes a vessel; a partitioning member which partitions the interior of the vessel into two chambers for accommodating a viscous fluid, and which rotates together with the vessel in a direction and is movable in an axial direction; a moving force imparting structure for imparting to the partitioning member a moving force in a direction by the input of rotation in a direction; a resilient structure for resiliently urging the partitioning member in a direction; a through hole for allowing the chambers inside the vessel to communicate with each other; and an allowing/limiting member which allows the viscous fluid to flow reciprocally between the chambers through the through hole, and which limits the flow of the viscous fluid in one chamber into the other chamber in the direction through the through hole.