PURPOSE: To improve tone quality and to obtain an inexpensive earphone, which has a satisfactory design and gives satisfactory feeling when the earphone is fitted by oscillating a diaphragm opposite to an electromagnet through a cavity with the electromagnet and a permanent magnet provided so as to surround the electromagnet and generating a voice.

CONSTITUTION: A hollow iron core 1 having transparent holes on both edges of its cylindrical part composes the electromagnet driven by a periodic current together with a winding 2. 3 is the permanent magnet provided so as to surround this electromagnet. Out of the rear space of a diaphragm 4, since the cylindrical space of the hollow iron core 1 works as acoustic quality, and space surrounded with a holder 6 and a housing 7 existing behind the cylindrical space works as acoustic capacity, the low frequency band of the acoustic characteristic of the earphone can be increased by setting the acoustic reactance so as to resonate in a desired low band frequency.