PURPOSE: To obtain an XY coordinate input device which is surely operated even at the time of quick operation or floating operation.

CONSTITUTION: A fixed roll 9 and two revolving rolls 2x and 2y orthogonal to each other are provided around a ball body 1 which is freely rotatably arranged, and one ends of revolving rolls 2x and 2y are pressed to the ball body 1 by deflecting means 8x and 8y. The movement in the horizontal direction of the ball body in a device is limited by the fixed roll 9 and a shake stopper 10. Consequently, the ball body 1 and revolving rolls 2x and 2y are not separated by the force applied to the ball body 1, and therefore, the extent of rotation of the ball body is surely detected even when the quick operation is performed or the operation is performed with the device floated.