A dynamic microphone unit includes: a diaphragm vibrating in response to received sound waves; a voice coil fixed to the diaphragm and vibrating in cooperation with the diaphragm; a magnetic circuit generating magnetism in a magnetic gap, the voice coil being disposed in the magnetic gap; a first air chamber defined adjacent to the reverse of the diaphragm; and a second air chamber defined behind the voice coil, the second air chamber being in communication with the first air chamber, an elastic thin-plate acoustic resistor being disposed in the second air chamber while having tensile force applied, at a position where the acoustic resistor limits the volume of the second air chamber and comes into contact with the voice coil within a maximum displacement of the voice coil.