To provide a sun-screening roller blind device for an automobile window which has a sure sun-screening action and a high stability for preventing a flapping motion from occurring when a blind sheet is let out, and can make a space-saving arrangement for the blind sheet possible under a housed state.

At least one blind sheet 2 is taken up by a shaft 3 under the housed state, and a pulling out element is provided at a pulling out end part 5. A side edge 6 of the blind sheet is arranged along a guide rail 10 on the side of a roller blind guiding frame under the let out state of the blind sheet 2 for this sun-screening roller blind device for an automobile window. Respective side edges 6 surround a guiding rod 8 arranged in respective guide rails on the sides just like a pocket, and can slide along the guide rods 8.