Lifting mechanism and key structure using the same

A key structure, comprising:

• a base plate comprising a first bottom wall;
• a key cap disposed opposite to the base plate and comprising a first cap wall;
• a lifting mechanism movably connected between the key cap and the base plate, so that the key cap reciprocates with respect to the base plate, wherein the lifting mechanism comprises a first lower shaft portion and a first upper shaft portion which are respectively movably connected on the same side of the base plate and the key cap;
• wherein when the key cap is in a released state, the first upper shaft portion presses against the first cap wall, but the first lower shaft portion is separated from the first bottom wall by a maintaining gap;
• wherein in a pressed state, the first lower shaft portion is separated from the first bottom wall by a bottom wall gap, the first upper shaft portion is separated from the first cap wall by a cap wall gap, and the cap wall gap is smaller than the bottom wall gap.