In a unidirectional microphone unit, stable frequency characteristics can be obtained, and manufacturing cost is reduced while preventing increasing of an external size. A microphone cap that covers a microphone element is included, and the microphone cap includes a porous ring member arranged in the front of the microphone element to form a first communication space communicating with a front acoustic hole in a center side, and a cylindrical member supporting a peripheral edge portion of the ring member and surrounding a periphery side of the microphone element, and forming a second communication space communicating with a rear acoustic hole in the periphery side of the microphone element, and the first communication space and the second communication space are communicated through the ring member.