PURPOSE: To facilitate the mounting and detaching of a liquid crystal substrate, etc., to and from a mounting part by a method wherein a weight part is pivotally fitted with the position of the gravity center of the weight part being outside so that a substrate holding pin part may tilt outside when the rotating unit is under a stationary state, and the substrate holding pin part may be put under a vertically standing state by a centrifugal force of the weight part when the rotating unit is under a rotating state.

CONSTITUTION: On the outside of a substrate mounting part 6 of a rotating unit 2, radial four arm parts 7 are provided in the horizontal direction, and under the center of the substrate mounting part 6, a bearing part 16 which attaches a rotating shaft 4 to transmit the rotating force of a motor to the rotating unit 2, is provided. An end part is formed into a recessed shape for the arm part 7, and on a protruding part 9 of the arm part 7, a hole 10 through which a shaft 15 passes, is provided. Also, on a valley-shaped part 11 of the arm part 7, an inhibiting part 12 which restricts the position of an approx. L-shaped weight part 13 so that a substrate holding pin part 8 with a cylindrical head part may become a vertically standing state when the rotating unit 2 is under a rotating state, is provided. Then, a pivotally fitted part 14 is provided on the weight part 13 which is supported by the substrate holding pin part 8, and the weight part 13 is pivotally fitted in the end part of the arm 7.