The invention relates to a key structure which comprises a bottom plate, a key cap arranged above the bottom plate, a supporting unit arranged between the key cap and the bottom plate and used for supporting the key cap to move relative to the bottom plate, a first magnetic piece arranged on the bottom plate, and a movable plate, wherein the movable plate can be rotationally arranged on the bottom plate in a manner of being parallel to the bottom plate and provided with a second magnetic piece, and magnetic attraction force is generated between the second magnetic piece and the first magnetic piece; when the key cap receives pressing force and moves towards the bottom plate, the supporting unit slides on the bottom plate for driving the movable plate to rotate in a manner of being parallel to the bottom plate and for enabling the second magnetic piece to leave from the first magnetic piece; when the pressing force is released, the magnetic attraction force enables the second magnetic piece to reversely rotate in a manner of being parallel to the bottom plate to get close to the first magnetic piece so as to drive the supporting unit to support the key cap to move and get far away from the bottom plate. According to the key structure, return force is provided by the first magnetic piece arranged below the key cap, the supporting unit arranged beside the first magnetic piece and the movable plate, and the familiar pressing hand feel of a user also can be obtained under lighting and thinning requirements.