A thin speaker having a magnetic circuit (2) disposed at the front of a cone-like diaphragm, wherein an internal magnetic type magnetic circuit (2) and a vibration system are supported by a sufficiently strong frame formed of two pieces having an outline of generally disk-shape and partly overlapped concentrically with each other, the acoustic characteristics are prevented from being deteriorated by preventing support bodies (7, 7A) for the magnetic circuit (2) from covering the forward of the sound emitting face of the cone-like diaphragm (3), and speaker component parts are formed so as to be assembled by stacking on one jig (1) from one direction with a specified procedure, whereby an assemblability can be improved.