A person's holding motion is assisted, at a sufficiently practical level, with a simple configuration. Provided is a motion assisting apparatus comprising a multijoint structure in which links in series are rotatably connected in a relative manner, and all of the links can be integrally deformed in a bendable manner, a linear member which is inserted through each of the links in the multijoint structure, wherein one end is fixed to the link in front and another end is elongated via the link in rear, a sliding/holding part which fixes an elongated portion of the linear member, and slidably guides the rear link in a connecting direction between each of the links, a drive unit which drives the rear link to slide toward the sliding/holding part and causes the multijoint structure, through which the linear member has been inserted, to engage in an extending motion or a flexing motion, and a control unit which drive-controls the drive unit so that a sliding direction, a sliding speed and a sliding position of the rear link will become an intended state.