PURPOSE: To provide a rotating signboard device which smoothly rotates a signboard in light wind as well as strong wind without problems of strength and buffetting (oscillation).

CONSTITUTION: A rotor (b) freely rotatably supported in a supporting frame body (a) is stood between a top plate 5 and a bottom plate 6 in the state that plural longitudinally long buckets 4 displaying a desired advertisement on the peripheral surfaces face one another with required air gaps (s) among them in parallel. A garter structure material (c) which has many top parts (or bottom parts) 7 by alternately bending a longitudinally band plate to the right and the left (or the front and the rear) is fitted to and laid in air gaps (s). A generator 13 is so connected and installed that it can be interlocked with the rotor (b).