A key switch structure can include a key top, a link structure, a back plate, a membrane sheet, an elastic member, an arm bar, and a pushing member. The link structure can guide the key top in the pushing direction while the key top is pushed. The back plate can support the link structure. The membrane sheet can include a contact portion arranged on the membrane sheet and connectable, in response to a predetermined pressure, to an electrical contact to form a closed circuit. The elastic member can push and separate the key top from the back plate, and be elastically deformable. The arm bar can movably support the key top, and the arm bar can be supported movably at the back plate. The pushing member can push the link structure while the key top is pushed.