A damper includes a vessel; a partitioning member which partitions an internal space of the vessel into two accommodation chambers for accommodating a viscous fluid and which is movable with respect to the vessel; a moving force imparting device for imparting to the partitioning member a moving force in an A1 direction by the input of rotation in an R2 direction with respect to the vessel, so that the moving velocity is set to one corresponding to the rotating velocity of that input of rotation; a resilient device for resiliently urging the partitioning member in an A2 direction; a communicating hole formed in the partitioning member; and a flow limiting device for limiting the flow of the viscous fluid in the accommodating chamber into the accommodating chamber through the communicating hole when the internal pressure of the viscous fluid accommodated in the accommodating chamber has exceeded a fixed value.