A take-up pipe 1 is placed along an upper edge of a window of a building and is rotatably supported by side brackets 2R. An upper end of the screen having a weight bar attached to a lower end thereof, is fixed to the take-up pipe, so that the take-up pipe is rotated in forward and reverse directions by a motor 5 to wind up and down the screen. A light receiving unit 27 to receive a pulsed optical signal applied from a remote controller is mounted on the side bracket and is arranged so that it can be switched to two different orientations where the light receiving directions are symmetric with respect to a vertically downward direction and the phases are different from each other. By virtue of this, irrespective of the installation constraint of the electric roll screen, the remote-control of the electric roll screen can be effected.