An electret condenser microphone comprising: a capsule that includes a first hollow cylinder and a front plate blocking one end face of the first hollow cylinder, the capsule being made of metal material; a diaphragm ring that has one surface in contact with an inner surface of the front plate and the other surface to which a diaphragm is attached; a back electrode plate that has a surface with which an electret dielectric film is coated, the surface facing the diaphragm, the back electrode plate being made of metal material; an insulating spacer that is annularly formed and present between the back electrode plate and the diaphragm to keep a space between the back electrode plate and the diaphragm; an impedance converter configured to perform impedance conversion of an electric signal generated on the back electrode plate and to extract the converted electric signal; a flexible printed circuit board in which a second hollow cylinder, a flange that projects radially from an edge of the second hollow cylinder on one end face of the second hollow cylinder that faces the back electrode plate, and a rear plate that blocks the other end face of the second hollow cylinder are integrally formed, the impedance converter being placed on a surface of the rear plate that faces the back electrode plate; and a gate ring that is cylindrically formed, is made of metal material, is present between the back electrode plate and the flexible printed circuit board to keep a space for housing the impedance converter between the back electrode plate and the flexible printed circuit board, and that is configured to electrically connect the back electrode plate to wiring on the flexible printed circuit board; wherein the diaphragm ring, the insulating spacer, the back electrode plate, the gate ring, and the flexible printed circuit board are laminated and housed in the capsule and an edge on an open side of the capsule is bent inward to fit against the flange of the flexible printed circuit board. a capsule that includes a first hollow cylinder and a front plate blocking one end face of the first hollow cylinder, the capsule being made of metal material; a diaphragm ring that has one surface in contact with an inner surface of the front plate and the other surface to which a diaphragm is attached; a back electrode plate that has a surface with which an electret dielectric film is coated, the surface facing the diaphragm, the back electrode plate being made of metal material; an insulating spacer that is annularly formed and present between the back electrode plate and the diaphragm to keep a space between the back electrode plate and the diaphragm; an impedance converter configured to perform impedance conversion of an electric signal generated on the back electrode plate and to extract the converted electric signal; a flexible printed circuit board in which a second hollow cylinder, a flange that projects radially from an edge of the second hollow cylinder on one end face of the second hollow cylinder that faces the back electrode plate, and a rear plate that blocks the other end face of the second hollow cylinder are integrally formed, the impedance converter being placed on a surface of the rear plate that faces the back electrode plate; and a gate ring that is cylindrically formed, is made of metal material, is present between the back electrode plate and the flexible printed circuit board to keep a space for housing the impedance converter between the back electrode plate and the flexible printed circuit board, and that is configured to electrically connect the back electrode plate to wiring on the flexible printed circuit board; wherein the diaphragm ring, the insulating spacer, the back electrode plate, the gate ring, and the flexible printed circuit board are laminated and housed in the capsule and an edge on an open side of the capsule is bent inward to fit against the flange of the flexible printed circuit board.