A special effect device by which an entirely new special picture effect is to be implemented in accordance with a read address control system. The device includes an address signal generating unit 3 which generates a readout address signal for picture signals stored in a frame buffer 2 so that, by rupturing a picture portion of an area at an optional position of a picture in the frame buffer, defined by a circle having a radius of an optional size, with the center of the circle as a rupturing point, a folded picture portion will be obtained which has the circumference of the circle as a topological boundary.