A keyboard includes a keycap, a pivot structure, a base and an X-structure. The keycap includes a bottom surface, a first edge and a second edge. The pivot structure includes two first engaging portions and two second engaging portions. The first engaging portions are disposed on the bottom surface and have a first distance away from the first edge. The second engaging portions are respectively disposed corresponding to the first engaging portions and have a second distance away from the second edge. The base is disposed under the keycap. One end of the X-structure is connected to the pivot structure of the keycap and the other end of the X-structure is movably connected to the base, thus, the keycap moves upward and downward corresponding to the base.