A micro speaker is disclosed. The micro speaker includes a diaphragm and a voice coil for driving the diaphragm, the diaphragm including a conductive dome and a suspension surrounding the conductive dome; a conductive front cover located adjacent to and keeping a distance from the conductive dome, the conductive front cover including a plurality of units being isolated from each other; and a plurality of capacitors formed by the units of conductive front cover and the conductive dome for outputting electrical signals according to vibrations of the diaphragm and for detecting real-time replacement of the diaphragm.