Abstract: A lever device may include a movable component including a pair of support arm portions and an operable knob including a base end portion arranged between the pair of support arm portions, the base end portion supported by the pair of support arm portions such that the base end portion is rotatable about a first axis line. The lever device may also include a fixed component including a polar board and a cover arranged in a direction of a second axis line perpendicular to the first axis line, the movable component supported by the fixed component such that the movable component is rotatable about the second axis line within the fixed component. The lever device may further include arc-shaped guide grooves. The pair of support arm portions may respectively include projections that engage the guide grooves.