A mouse device includes a button, a switch, a linkage element, a plate body, a supporting element and an adjusting element. A triggering part of the plate body is arranged between the linkage element and the switch. When the adjusting element is moved, the supporting element is correspondingly moved. Consequently, the supporting element is selectively contacted with the first fulcrum or the second fulcrum. While the button is pressed down and the linkage element is moved downwardly toward the triggering part, the triggering part is swung around a first fulcrum or a second fulcrum of the plate body to push the switch. Consequently, the switch is triggered.