There is provided an acoustic diaphragm used for a loudspeaker, having an injection-molded edge molded using a thermoplastic elastomer, in which the edge is formed using a workable polyolefinic elastomer, as a material, containing a soft segment having rubber particles of 1 μm to 10 μm in diameter uniformly dispersed therein, and a hard segment composed of an olefinic resin, and the edge is formed into a shape allowing the resin to be aligned as being not causative of anisotropy in the physical characteristics of the edge, as a result of thin-wall molding by the injection molding.