The invention relates to a circuit board which comprises an inner layer structure, a first outer layer structure and an electromagnetic shielding material. The inner layer structure comprises a first inner layer circuit. The first inner layer circuit comprises an electromagnetic shielding connection pad. A copper plating layer is formed on the surface of the electromagnetic shielding connection pad. The first outer layer structure is formed on the surface of the first inner layer line and the copper plating layer. The copper plating layer completely covers the electromagnetic shielding connection pad and is partially embedded in the first outer layer structure. A U-shaped groove is formed from the surface, which is away from the electromagnetic shielding connection pad, of the copper plating layer to the inside copper plating layer. The first outer layer structure is provided with an opening corresponding to the U-shaped groove. The U-shaped groove and the opening are filled with the electromagnetic shielding material. The present invention also relates to a method of manufacturing the circuit board.