An electro-acoustic transducer (1, 2, 3) comprising: a diaphragm (14, 14a); a device casing which is formed with an opening in a part thereof for supporting therein the diaphragm (14, 14a) so as to allow the diaphragm (14, 14a) to vibrate; a first magnet (12, 12a) which is provided on a side of the opening with respect to the diaphragm (14, 14a) and polarized in a vibration direction of the diaphragm (14, 14a); a second magnet (13, 13a, 13b, 13c, 13d) which is provided on a side of an inner bottom surface of the device casing with respect to the diaphragm (14, 14a) so that the diaphragm (14, 14a) is interposed between the first magnet (12, 12a) and the second magnet (13, 13a, 13b, 13c, 13d) and which is polarized in a direction opposite to a polarization direction of the first magnet (12, 12a); and a drive coil (15, 15a) which is provided on the diaphragm (14, 14a) so as to be located in a magnetic gap formed by a pair of the first and second magnets (13, 13a, 13b, 13c, 13d) for generating a driving force which causes the diaphragm (14, 14a) to vibrate, wherein when the first (12, 12a) and second magnets (13, 13a, 13b, 13c, 13d) are projected on the diaphragm (14, 14a), a first projected area of the first magnet (12, 12a) is smaller than a second projected area of the second magnet (13, 13a, 13b, 13c, 13d), the diaphragm (14, 14a) has an elongated shape in which a width in a lateral direction thereof is smaller than that in a longitudinal direction thereof, the drive coil (15, 15a) has an elongated shape in which a width in a lateral direction thereof is smaller than that in a longitudinal direction thereof, and is provided on the diaphragm (14, 14a) so that the longitudinal direction of the drive coil (15, 15a) is parallel to that of the diaphragm (14, 14a), the drive coil (15, 15a) and the diaphragm (14, 14a) are disposed so that a central axis of the drive coil (15, 15a) in a vibration direction thereof substantially coincides with that of the diaphragm (14, 14a) in the vibration direction thereof, wherein a center position in a region on the diaphragm (14, 14a) on which a coil wire of the drive coil (15, 15a) is disposed is located at a position, which is outward of an outer periphery of the surface of the first magnet (12, 12a) which faces the diaphragm (14, 14a), and inward of an outer periphery of the surface of the second magnet (13, 13a, 13b, 13c, 13d) which faces the diaphragm (14, 14a). a diaphragm (14, 14a); a device casing which is formed with an opening in a part thereof for supporting therein the diaphragm (14, 14a) so as to allow the diaphragm (14, 14a) to vibrate; a first magnet (12, 12a) which is provided on a side of the opening with respect to the diaphragm (14, 14a) and polarized in a vibration direction of the diaphragm (14, 14a); a second magnet (13, 13a, 13b, 13c, 13d) which is provided on a side of an inner bottom surface of the device casing with respect to the diaphragm (14, 14a) so that the diaphragm (14, 14a) is interposed between the first magnet (12, 12a) and the second magnet (13, 13a, 13b, 13c, 13d) and which is polarized in a direction opposite to a polarization direction of the first magnet (12, 12a); and a drive coil (15, 15a) which is provided on the diaphragm (14, 14a) so as to be located in a magnetic gap formed by a pair of the first and second magnets (13, 13a, 13b, 13c, 13d) for generating a driving force which causes the diaphragm (14, 14a) to vibrate, wherein when the first (12, 12a) and second magnets (13, 13a, 13b, 13c, 13d) are projected on the diaphragm (14, 14a), a first projected area of the first magnet (12, 12a) is smaller than a second projected area of the second magnet (13, 13a, 13b, 13c, 13d), the diaphragm (14, 14a) has an elongated shape in which a width in a lateral direction thereof is smaller than that in a longitudinal direction thereof, the drive coil (15, 15a) has an elongated shape in which a width in a lateral direction thereof is smaller than that in a longitudinal direction thereof, and is provided on the diaphragm (14, 14a) so that the longitudinal direction of the drive coil (15, 15a) is parallel to that of the diaphragm (14, 14a), the drive coil (15, 15a) and the diaphragm (14, 14a) are disposed so that a central axis of the drive coil (15, 15a) in a vibration direction thereof substantially coincides with that of the diaphragm (14, 14a) in the vibration direction thereof, wherein a center position in a region on the diaphragm (14, 14a) on which a coil wire of the drive coil (15, 15a) is disposed is located at a position, which is outward of an outer periphery of the surface of the first magnet (12, 12a) which faces the diaphragm (14, 14a), and inward of an outer periphery of the surface of the second magnet (13, 13a, 13b, 13c, 13d) which faces the diaphragm (14, 14a).