PURPOSE: To increase the damping force by forming a shearing force generating surface, including a bulging part which bulges towards other shearing force generating surface and specifying the interval between the shearing force generating surface and the other shearing force generating surface.

CONSTITUTION: A viscous damper 1 is constituted of a case 10, viscous material 20, and the second damping force generating body 30. A shearing force generating surface 14 is allowed to approach the second damping force generating body 30 by a bulging part 13. While, even if the second damping force generating body 30 is bent by receiving a shearing force in the X direction, the interval between the shearing force generating surface 14 and other shearing force generating surface 33 is set so that the second damping force generating body 30 and the shearing force generating surface 14 do not contact. Therefore, a large damping force can he obtained without damaging the second damping force generating body 30, bulging part 13, and a flat plate 11 by this contact.