To adopt viscous coupling in a suspension device.

This suspension device includes a viscous coupling 10 at a joint part of a link mechanism. The viscous coupling 10 comprises a shaft 20a, a case body 12 housing viscous fluid, and a plate generating an attenuating force according to relative rotation of the shaft 20a and the case body 12. The shaft 20a has a first shaft 24 and a second shaft 28 rotatable relatively, and a first elastic body energizing the first shaft 24 and the second shaft 28 so that the both ends restrain the relative rotation. When the first elastic body receives a load with not less than a predetermined value, the first shaft 24 and the second shaft 28 rotate relatively.