An image reading apparatus capable of preventing the occurrence of a streak and reading a quality image from the leading edge to the trailing edge of a original. An original is conveyed along a convey pass. The original being conveyed is guided by a guide member, at least part of the guide member being transparent. An image of the original being conveyed is read by an image sensor through the guide member. Airflow is generated, the airflow being blown into the convey pass from a location upstream in a conveying direction compared to a location of the image sensor. The guide member has a convex portion disposed at a location upstream in the conveying direction compared to the location of the image sensor.