An arm module having a structure capable of precisely moving each link unit while flexibly moving with sufficient stiffness includes a plurality of link units each having a ring shape, a plurality of joint units each disposed in a middle portion of a corresponding one of the plurality of link units to connect the plurality of link units, wherein the plurality of link units includes a first link unit, a second link unit disposed while being rotated with respect to the first link unit, the second link unit linked at an upper side of the first link unit while passing through a middle portion of the first link unit, and a third link unit disposed while being rotated with respect to the second link unit, the third link unit linked at an upper side of the second link unit while passing through a middle portion of the second link unit.
