Abstract: A diaphragm for electro-acoustic transducer comprising a core member of honeycomb structure made of either a thin film of a metal or a high molecular material, and a skin member bonded to at least one side of this honeycomb core structure and being prepared by the use of aromatic polyamide fibers having a high tensile strength, a high Young's modulus and a high Young's modulus-to-weight ratio and reinforced by a thermo-setting resin. Such diaphragm has a high Young's modulus, an improved mechanical strength and a wide frequency range of piston motion, and presents reduced distortion throughout a wide frequency range, and has a superior transition characteristic, whereby a good sound reproduction characteristic is obtained.