An electroacoustic transducer serving as a speaker or a microphone is reduced in size and weight and is capable of generating sound with relatively high sound pressure. It is constituted of a housing having a cavity having an opening in the exterior, a fixed electrode positioned opposite to the opening of the housing, a diaphragm having an electrode positioned between the opening and the fixed electrode, and an elastic deformation portion for supporting the diaphragm with respect to the housing and for allowing the diaphragm to vibrate in the thickness direction. The fixed electrode is electrically insulated from the electrode of the diaphragm. The diaphragm is distanced from the fixed electrode by means of the elastic deformation portion placed in the balanced state. When the elastic deformation portion is subjected to elastic deformation, the diaphragm vibrates with relatively large amplitude such that it comes in contact with the fixed electrode.