Abstract: An illuminated keyswitch includes a keycap, a pair of frames adapted to support the keycap in an up-down movement, the pair of frames disposed corresponding to each other and substantially rotatably coupled to each other to define an inner space under the keycap, a pair of elastic members connecting the pair of frames to be located at two opposite sides of the inner space, respectively, and an illumination light source disposed between the pair of elastic members in the inner space and adapted to provide an illumination light. During the up-down movement of the keycap, a vertical projection of the pair of frames surrounds the inner space without interfering therewith, so the illumination light passes the inner space to illuminate the keycap.