A MEMS microphone includes a cover, a housing engaging with the cover for forming a cavity, at least one transducer accommodated in the cavity, and a conductive case covering the cover and the sidewall of the housing. The housing includes a cover and a sidewall extending from the base. The conductive case defines a first part covering the cover, a second part extending from the first part for covering the sidewall and a third part perpendicularly extending from the second part for covering a periphery part of the base, the third part forming an opening.