A photographing module includes an imaging lens assembly. The imaging lens assembly includes a plurality of lens elements, wherein one of the lens elements is a plastic lens element. At least one surface of an object-side surface and an image-side surface of the plastic lens element includes an effective optical portion and a peripheral portion. The peripheral portion surrounds the effective optical portion, and includes a plurality of rib structures, a first fitting section and an isolation section. Each of the rib structures has a strip shape along a radial direction of an optical axis of the imaging lens assembly, and the rib structures are arranged around the effective optical portion. The first fitting section surrounds the effective optical portion, and is connected to another one of the lens elements adjacent to the surface. The isolation section is disposed between the rib structures and the first fitting section.