The purpose of the present invention is to enable a pair of gripping pieces to be opened and closed using a single wire and to achieve reductions in diameter and cost. This gripping mechanism (3) is equipped with: two gripping pieces (5, 6) that are made to swing relative to each other around a swing shaft (A1) a base member (2) that swingably supports at least one of the gripping pieces (5, 6) a traction pulley (7) that is supported so as to be able to rotate around a rotation shaft (A2) that is parallel to the swing shaft (A1) a wire (8) that is wound around the traction pulley, that has one end thereof fixed to a gripping piece or the base member, and that is caused to apply a tensile force that causes the rotation shaft to move in one direction by a traction force applied to the other end thereof, or transmits a pressing force applied to the other end thereof and a force receiving part (8c) that receives a pressing force. The traction pulley is disposed such that the total tensile force of the wire acting on the rotation shaft generates a moment that causes the gripping pieces to swing in a direction in which the gripping pieces close relative to each other. The force receiving part is disposed such that the pressing force received from the wire generates a moment that causes the gripping pieces to swing in a direction in which the gripping pieces open relative to each other.Lobjectif de la présente invention est de permettre quune paire de pièces de préhension soient ouvertes et fermées au moyen dun fil unique et dobtenir des réductions de diamètre et de coût. Ce mécanisme de préhension (3) est équipé de : deux pièces de préhension (5, 6) qui sont amenées à osciller lune par rapport à lautre autour dun arbre de pivotement (A1) un élément de base (2) qui soutient de façon pivotante au moins une des pièces de préhension (5, 6) une poulie de traction (7) qui est soutenue de façon à pouvoir tourner autour dun arbre de rotation (A2) qui est parallèle à larbre dosc
