A rotary-wing aircraft comprising: a plurality of rotary wings (12A; 12B; 12C; 12D;) having rotary shafts arranged on a circle defining the center of a center U of lift of the rotary-wing aircraft; arm portions (14A; 14B; 14C; 14D) that support the plurality of rotary wings (12A; 12B; 12C; 12D); a first mounting portion for mounting an object; a second mounting portion ; a connecting portion that connects the first mounting portion and the second mounting portion via support rods , and that connects the first mounting portion and the second mounting portion to the arm potions , the second mounting portion being disposed on an opposite side to the first mounting portion as viewed from the connecting portion , the support rods being one rod-like member extending in one direction, and being swingable, with respect to the body, around the connecting portion , characterized in that a center-of-gravity moving mechanism for moving a center of gravity of the body is provided, the first mounting portion , the second mounting portion , and the support rods being vertically movable with respect to the connecting portion ; a center U of lift generated in the rotary-wing craft by rotation of the plurality of rotary wings (12A; 12B; 12C; 12D) coincides with a center C of rotation of the connecting portion defined by the center of the circle on a plane passing through the position of d/3 from the upper end of each of the rotary wings in the axial direction thereof and through which the rotation shafts of the rotary wings pass, when the height in the axial direction of each of the rotary wings (12A, 12B, 12C, and 12D) is d. a plurality of rotary wings (12A; 12B; 12C; 12D;) having rotary shafts arranged on a circle defining the center of a center U of lift of the rotary-wing aircraft; arm portions (14A; 14B; 14C; 14D) that support the plurality of rotary wings (12A; 12B; 12C; 12D); a first mounting portion for mounting an object; a second mounting portion ; a connecting portion that connects the first mounting portion and the second mounting portion via support rods , and that connects the first mounting portion and the second mounting portion to the arm potions , the second mounting portion being disposed on an opposite side to the first mounting portion as viewed from the connecting portion , the support rods being one rod-like member extending in one direction, and being swingable, with respect to the body, around the connecting portion , characterized in that a center-of-gravity moving mechanism for moving a center of gravity of the body is provided, the first mounting portion , the second mounting portion , and the support rods being vertically movable with respect to the connecting portion ; a center U of lift generated in the rotary-wing craft by rotation of the plurality of rotary wings (12A; 12B; 12C; 12D) coincides with a center C of rotation of the connecting portion defined by the center of the circle on a plane passing through the position of d/3 from the upper end of each of the rotary wings in the axial direction thereof and through which the rotation shafts of the rotary wings pass, when the height in the axial direction of each of the rotary wings (12A, 12B, 12C, and 12D) is d. <EOS>