Voice coil body of a loudspeaker is provided at the outer circumferential wall surface with a supporting section. Diameter of the inner circumference of suspension holder is greater than outer diameter of the voice coil body while diameter of the inner circumference of diaphragm is greater than diameter of the inner circumference of suspension holder for facilitating a gluing of the inner circumferential end of suspension holder and the inner circumferential end of diaphragm on the supporting section and to the voice coil body. By so doing, harmonic distortion of a loudspeaker can be further reduced.