Excellent narrow-angle directivity is obtained by causing a microphone case main body to function as an acoustic tube, reducing a weight of a microphone, and suppressing leakage of sound waves from an inside of the acoustic tube to an outside. An acoustic tube microphone case includes a microphone case main body made of a metal tube having a plurality of openings formed in a peripheral surface, and acoustic resistance materials formed in a rectangular sheet manner, cylindrically rounded such that both right and left ends are mutually in contact, and arranged along an inner peripheral surface of the microphone case main body. A plurality of the acoustic resistance materials is layered, and at least the innermost acoustic resistance material applies a force in a developing direction by an elastic force thereof, and presses the outside acoustic resistance materials against the inner peripheral surface of the microphone case main body.