An input device includes a ball having a magnetic body therein. The magnetic body includes projections radially extending from the core toward the outer periphery of the ball. The device also includes a ring magnet and magnet detection elements surrounded by a lower area of the ball so as to be opposite thereto. The structure allows the input device to be protected from dust and dirt during long-term use so as to maintain a good tactile feel in a simple structure. Because, the input device has no components such as rollers that are in contact with the ball.