An electrical interconnecting structure suitable for a circuit board is provided. The electrical interconnecting structure includes a core, an ultra fine pattern, and a patterned conductive layer. The core has a surface, and the ultra fine pattern is inlaid in the surface of the core. The patterned conductive layer is disposed on the surface of the core and is partially connected to the ultra fine pattern. Since the ultra fine pattern of the electrical interconnecting structure is inlaid in the surface of the core and is partially connected to the patterned conductive layer located on the surface of the core.