One of the conventional types of the wing structure is composed of the spars, the ribs, and the flexible membrane skins. A deformation of the membrane affects aerodynamic characteristics of the wing. The deformation state varies depending on the structure of the rigid part of the wing. This study investigates the effects of the shape of the rigid part of the spar-rib-skin structure wing on the aerodynamic characteristics and deformation characteristics. The result of the wind tunnel tests shows that the deformation and change of the aerodynamic characteristics decreased as the number of the ribs increased. The result also suggests that the flexibility of the trailing edge affects the pitching moment characteristics.