The present invention discloses a keyboard device. The keyboard device includes a sheet, a membrane switch, an actuating component, and a protrusion keycap structure. The membrane switch is disposed on a side of the sheet. The actuating component is disposed on a side of the membrane switch far away from the sheet and is for pressing the membrane switch to actuate the membrane switch. The protrusion keycap structure is disposed on a side of the actuating component far away from the membrane switch and is for driving the actuating component to actuate the membrane switch upon being pressed. The protrusion keycap structure includes a mylar film.