The invention discloses a key structure including a keycap, a base plate, and a support member. The keycap includes a slide part; the base plate includes an engagement part; the support member includes a first end and a second end for engaging the keycap and the base plate. The first end slides on the slide part, and the second end is engaged to the engagement part. Therein, the second end thereon defines a first direction and a second direction perpendicular to the first direction. The first and second directions are substantially parallel to the base plate. The engagement part restrains the second end from sliding along the first direction. The second end includes two block parts. The block parts are deposited on two sides of the engagement part for restraining the second end from sliding along the second direction.