It is an object of the present invention to provide a linear motion link device capable of reducing a load applied to an actuator and capable of saving consumption of power and a bipedal walking robot provided therewith. Therefore, this is why the linear motion link device is held and locked by a holding brake so as not to telescope during the stop of the actuator. The linear motion link device of the present invention is constituted so as to include an actuator (28) and a holding brake (30) which holds and locks a movable portion (41) of the actuator (28) and to freely telescope in a longitudinal direction of the linear motion link device (1) by driving of the actuator (28). Further, a bipedal walking robot of the present invention has a constitution that the linear motion link device (1) having the holding brake (30) which holds and locks the movable portion (41) of the actuator (28) is provided.