Thin keyboard

A thin keyboard, comprising:

• a circuit board including a plurality of command portions to receive contact to generate command signals and a plurality of elastic support members located on the command portions;
• a plurality of keycaps positioned corresponding to the elastic support members, each keycap including at least one depressible press surface and a holding surface opposed the press surface and formed at an elevation difference interval with the press surface, the transverse cross section of the holding surface greater than the transverse cross section of the press surface;
• and
• a frame corresponding to the keycaps and including a plurality of installation portions corresponding to the keycaps, and a plurality of ribs abutting the circumference of the installation portions and overlapped over the holding surface of each keycap, each installation portion having a carved out area which is smaller than the holding surface;
• whereby the installation portions and the ribs confine positioning and movement of the keycaps.