To fully automate installation work by providing on a base a centering device which detects the distance over which a tire placed on an elevator platform is raised to a mounting tool, and forming, at the end of the arm of a slider provided in the device, a contact part which makes contact with the inner peripheral surface of a wheel and a tire bead.

When a start button is depressed while a tire is put on an elevator platform 11, a centering device 16 operates to detect height, and the elevator platform 11 is raised by a lift 9. Then a moving base 7 is moved to check a wheel 5 with a mounting tool 4. Then a main spindle rotates, and the moving base 7 is further moved to cause bead rollers 8a, 8b to press the tire to remove the tire from the wheel 5. The centering device 16 is designed to be capable of calculating the height to the center of the mounting tool 4 by measuring the height position of the tire put on the elevator platform 11. Also, a vertically movable slider 22 is provided, and a contact part 24 is formed at the end of an arm 17 extended form the slider 22.