To automatically operate a retractable awning of a type to be placed on a vertical supporting surface, by an electric motor.

A retractable awning assembly 10 having power and being automatically operated is composed of a roller assembly 16 attached to a supporting wall 12 and used for winding and spreading awning cloth or a canopy 14 for selectively covering a region adjacent to a supporting wall 12 and left- right arm assemblies 18 for supporting end sections on both sides of the roller assembly 16. A torsion-spring urging a roller so that the canopy is rolled into the roller is connected to the first end section in the roller, and the roller can also be rotated in either direction by an electric motor.