The present invention discloses a dashpot which is provided with the following: a valve disc that partitions the dashpot into two chambers; a channel that is formed in the valve disc and joins the two chambers; a window that is formed in the valve disc and connects to the channel; a valve seat that is formed in the valve disc and encircles the window; and a plurality of ring-shaped leaf valves stacked on the valve disc. The first leaf valve stacked on the valve disc is provided such that the outside edge thereof can be seated against and can separate from the valve seat, and said first leaf valve is provided with a rib in a position opposite the valve seat. Said rib protrudes away from the valve disc, and the valve-disc side of the rib is recessed.