A joint structure for a robot including a four-link mechanism, in which an elastic member expands and its restoring force increases as a finger is bent, and a distance between a second straight line passing through a center of a second rotation shaft and a fixed point at which the other end of the elastic member is fixed to the third link is equal to or longer than a distance between a fourth straight line passing through a center of a first rotation shaft and a fixed point at which one end of the elastic member is fixed to the second link, the second straight line being perpendicular to a first straight line passing through centers of second and fourth rotation shafts, and the fourth straight line being perpendicular to a third straight line passing through centers of first and third rotation shafts.