An object of the present invention is to provide an electroacoustic transducer having a multi-channel diaphragm, and a hearing aid using the electroacoustic transducer, in which a plurality of channels having different resonant frequencies is formed in the diaphragm using MEMS technology, thus more closely approximating the different audible frequency characteristics of respective persons. The present invention provides an electroacoustic transducer provided with a multi-channel diaphragm. The electroacoustic transducer includes a diaphragm (110) and signal conversion units (120). The diaphragm is provided with respective channels having different resonant frequencies. The signal conversion units are attached to surfaces channels of the channels, or are arranged to be spaced apart from the surfaces of the channels at a predetermined interval, the signal conversion units converting vibration received from the channels into acoustic signals, or transmitting acoustic signals to the diaphragm and converting the acoustic signals into vibration.