A loud speaker includes a circuit board and a base. The circuit board includes a plurality of contacts on a side thereof. The base is formed of plastic material by injection molding. The base includes an insertion groove in an end thereof. The circuit board is embedded in the insertion groove. The base further includes a plurality of grooves in communication with the insertion groove. The grooves are respectively aligned with the contacts of the circuit board. The circuit board is placed in a mold for forming the base and the circuit board is embedded in the base after formation of the base by injection molding.