A link actuation device comprising: a proximal end side link hub ; a distal end side link hub ; and three or more link mechanisms , each coupling the distal end side link hub to the proximal end side link hub such that a posture of the distal end side link hub is variable relative to the proximal end side link hub , wherein each of the link mechanisms includes: a proximal side end link member having one end thereof rotatably coupled to the proximal end side link hub ; a distal side end link member having one end thereof coupled to the distal end side link hub ; and an intermediate link member having opposite ends thereof rotatably coupled to other ends of the proximal side end link member and the distal side end link member , respectively, each of the link mechanisms has such a shape that a geometric model of the link mechanism represented by straight lines shows symmetry between a proximal end side portion thereof and a distal end side portion thereof with respect to a center portion of the intermediate link member , two or more link mechanisms among the three or more link mechanisms are each provided with an actuator which arbitrarily changes the posture of the distal end side link hub relative to the proximal end side link hub , and an end effector is disposed in one of the proximal end side and distal end side link hubs so as to face inside of arrangement of the proximal end side link hub and the distal end side link hub , and the end effector performs work onto a workpiece disposed on the other of the proximal end side and distal end side link hubs, wherein the end effector is disposed on the distal end side link hub , a work hole which allows the end effector to be inserted therein is provided in the proximal end side link hub , and the end effector inserted in the work hole performs work onto the workpiece which is directly or indirectly supported by the proximal end side link hub and which is located to a proximal end side relative to the proximal end side link hub . a proximal end side link hub ; a distal end side link hub ; and three or more link mechanisms , each coupling the distal end side link hub to the proximal end side link hub such that a posture of the distal end side link hub is variable relative to the proximal end side link hub , wherein each of the link mechanisms includes: a proximal side end link member having one end thereof rotatably coupled to the proximal end side link hub ; a distal side end link member having one end thereof coupled to the distal end side link hub ; and an intermediate link member having opposite ends thereof rotatably coupled to other ends of the proximal side end link member and the distal side end link member , respectively, each of the link mechanisms has such a shape that a geometric model of the link mechanism represented by straight lines shows symmetry between a proximal end side portion thereof and a distal end side portion thereof with respect to a center portion of the intermediate link member , two or more link mechanisms among the three or more link mechanisms are each provided with an actuator which arbitrarily changes the posture of the distal end side link hub relative to the proximal end side link hub , and an end effector is disposed in one of the proximal end side and distal end side link hubs so as to face inside of arrangement of the proximal end side link hub and the distal end side link hub , and the end effector performs work onto a workpiece disposed on the other of the proximal end side and distal end side link hubs, wherein the end effector is disposed on the distal end side link hub , a work hole which allows the end effector to be inserted therein is provided in the proximal end side link hub , and the end effector inserted in the work hole performs work onto the workpiece which is directly or indirectly supported by the proximal end side link hub and which is located to a proximal end side relative to the proximal end side link hub . <EOS>