PURPOSE: To provide a general-purpose rotary support base which is lightweight, thin, and strong with a simple structure.

CONSTITUTION: A cylindrical rotary shaft is formed upward at nearly the center of a fixed plate 2, and a cylindrical rotary coupling section rotatably supported on the rotary shaft is formed downward at nearly the center of a rotary plate 6. A circular outer projection 4 is protruded in the same direction as the rotary fitting section outside the rotary plate 6, and a circular rail 5 having a substantially U-shaped cross section is protruded at the prescribed interval inside the outer projection 4. An inner projection 8 entering between the outer projection 4 and the rail 5 is protruded at the outer peripheral edge section of the fixed plate 2.