A multi-finger grasping mechanism (300), comprising three two-joint finger units (1-1 to 1-3). Each two-joint finger unit further comprises a finger root part (2), a finger root side joint part (5), a finger intermediate part (3), a finger tip side joint part (6), and a finger tip part (4). The finger intermediate part (3) can be swung about the joint axis (5a) of the finger root side joint part (5), and the finger tip part (4) can be swung about the joint axis (6a) of the finger tip side joint part (6). The finger tip part (4) can be swung about the center axis thereof. When a bolt (W) is held by the finger tip part (4) and the finger part (4) is rotated, the tightening operation of the bolt (W) can be performed.