An auxiliary washing machine comprising a cabinet that defines an accommodation space, a washing unit configured to be withdrawn from the cabinet, and a front panel that is located in front of the washing unit and defines a front external appearance of the auxiliary washing machine, wherein the washing unit comprises: a drawer configured to be accommodated in the accommodation space of the cabinet, the drawer defining a space for storage of wash water; a rotating structure placed within the drawer, the rotating structure having a rotating shaft penetrating the drawer so as to treat laundry; and a suspension assembly configured to support vertical load of the rotating structure such that the rotating structure is supported to float with respect to the drawer and to alleviate horizontal vibration of the rotating structure; wherein the drawer includes a drawer body corresponding to the accommodation space of the cabinet and a tub structure placed within the drawer body such that wash water is stored in the tub structure; wherein the tub structure includes: a ring-shaped bottom portion defining a bottom surface of the tub structure, the bottom portion having a center aperture; and a moving piece located in the aperture of the bottom portion so as to be movable relative to the bottom portion; wherein a bearing housing is located below the moving piece so as to support the rotating shaft, and the suspension assembly supports the bearing housing such that the bearing housing is mounted to the drawer body, wherein the bearing housing includes three or more bracket coupling portions (451a, 451b, 451c) radially extending from the bearing housing, wherein the drawer body includes three or more holders (425a, 425b, 425c) arranged at positions corresponding to the respective bracket coupling portions (451a, 451b, 451c), wherein the suspension assembly is provided between the bracket coupling portions (451a, 451b, 451c) and the holders to support the bearing housing in a floated state, and wherein the suspension assembly includes a bracket (461a, 461b, 461c) coupled to each of the bracket coupling portions (451a, 451b, 451c), and a support bar having an upper end rotatably coupled to the holder (425a, 425b, 425c) and a lower end rotatably connected to the bracket (461a, 461b, 461c), wherein a moving gasket is provided between the bottom portion and the moving piece and configured to seal a gap between the bottom portion and the moving piece and to allow the moving piece to be movable relative to the bottom portion. a drawer configured to be accommodated in the accommodation space of the cabinet, the drawer defining a space for storage of wash water; a rotating structure placed within the drawer, the rotating structure having a rotating shaft penetrating the drawer so as to treat laundry; and a suspension assembly configured to support vertical load of the rotating structure such that the rotating structure is supported to float with respect to the drawer and to alleviate horizontal vibration of the rotating structure; wherein the drawer includes a drawer body corresponding to the accommodation space of the cabinet and a tub structure placed within the drawer body such that wash water is stored in the tub structure; wherein the tub structure includes: wherein the drawer includes a drawer body corresponding to the accommodation space of the cabinet and a tub structure placed within the drawer body such that wash water is stored in the tub structure; wherein the tub structure includes: a ring-shaped bottom portion defining a bottom surface of the tub structure, the bottom portion having a center aperture; and a moving piece located in the aperture of the bottom portion so as to be movable relative to the bottom portion; wherein a bearing housing is located below the moving piece so as to support the rotating shaft, and the suspension assembly supports the bearing housing such that the bearing housing is mounted to the drawer body, wherein the bearing housing includes three or more bracket coupling portions (451a, 451b, 451c) radially extending from the bearing housing, wherein the drawer body includes three or more holders (425a, 425b, 425c) arranged at positions corresponding to the respective bracket coupling portions (451a, 451b, 451c), wherein the suspension assembly is provided between the bracket coupling portions (451a, 451b, 451c) and the holders to support the bearing housing in a floated state, and wherein the suspension assembly includes a bracket (461a, 461b, 461c) coupled to each of the bracket coupling portions (451a, 451b, 451c), and a support bar having an upper end rotatably coupled to the holder (425a, 425b, 425c) and a lower end rotatably connected to the bracket (461a, 461b, 461c), wherein a moving gasket is provided between the bottom portion and the moving piece and configured to seal a gap between the bottom portion and the moving piece and to allow the moving piece to be movable relative to the bottom portion.