A microphone unit converts voice into an electric signal based on the vibration of a diaphragm contained in an MEMS chip. The microphone unit includes a substrate on which the diaphragm is mounted (the MEMS chip is mounted); a cover member, having sound holes, that is disposed above the substrate so that the diaphragm is contained within the inner space formed between the cover member and the substrate; and a holding member that holds only the substrate or both of the substrate and the cover member.