In a method of manufacturing a thin keypad of a keypad panel having a smooth surface, a mist surface or a lines layer, the method includes the steps of: preparing a mold with an internal bottom surface of a coarse surface, a smooth surface or a lines surface; applying an adhesive into the mold and coating a carrier onto the surface of the adhesive; rolling the surface of the carrier by a roller to level the adhesive in the mold; performing a ultraviolet projection to cure the adhesive to form a keypad layer on the carrier; filming a ground color layer, a function color layer and a font color layer sequentially on the carrier as the background of the keypad panel; and hot pressing and combining the keypad layer and silicon to produce the keypad panel.