Keyboard device and key structure thereof

A keyboard device comprising plural key structures, each of the plural key structures comprising:

• a base plate;
• a keycap located over the base plate, and comprising a top wall and a skirt part, wherein the skirt part is protruded from a periphery region of the top wall and extended toward the base plate;
• a membrane circuit board arranged between the keycap and the base plate, and comprising at least one pressure sensing structure;
• and
• an elastic plate arranged between the keycap and the membrane circuit board, and comprising at least one triggering part, wherein the at least one triggering part is extended toward the membrane circuit board, and aligned with the at least one pressure sensing structure,
• wherein while the keycap is moved downwardly toward the elastic plate, the skirt part of the keycap is correspondingly moved to press the elastic plate, and the elastic plate is subjected to deformation, so that the at least one triggering part is moved downwardly to press the at least one pressure sensing structure.