According to embodiments of the disclosure, a flexible device and a fabrication method thereof are provided. The flexible device has a first area and a second area, and the stiffness of a portion of the first area is greater than the stiffness of the second area. The flexible device may include a flexible substrate and a rigid element. The flexible substrate includes a first surface and a second surface opposite to each other. The second surface has a coarse structure. The surface roughness of the second surface is greater in the first area than in the second area. The rigid element is disposed on the first surface of the flexible substrate and located in the first area. The stiffness of the rigid element is greater than the stiffness of the flexible substrate. A projection area of the coarse structure on the flexible substrate overlaps an area of the rigid element.