A manufacturing method of an acoustic sensor including a semiconductor substrate including a back chamber; a conductive diaphragm arranged on the upper side of the semiconductor substrate; an insulating fixed film fixed on an upper surface of the semiconductor substrate, the insulating fixed film covering the diaphragm such that a gap is formed between the insulating fixed film and the diaphragm; a conductive fixed electrode film arranged on the insulating fixed film at a position facing the diaphragm; and an electrode terminal (45, 46) for outputting change in electrostatic capacitance between the fixed electrode film and the diaphragm to outside as an electric signal; the manufacturing method comprising the steps of: forming the diaphragm inside a sacrifice layer deposited on the upper surface of the semiconductor substrate; forming, by etching the sacrifice layer, a space shaping portion having a shape of an inner surface of the insulating fixed film, and a thick film layer on an outer side of the space shaping portion separated from the space shaping portion; subsequently forming an adhesive layer on an outer side of the thick film layer so as to cover a dicing street part of the upper surface of the semiconductor substrate by the adhesive layer wherein the adhesive layer is thinner than the thick film layer; forming the insulating fixed film on the space shaping portion and covering the thick film layer and the adhesive layer with a protective film made from a material identical to the insulating fixed film; forming the back chamber in the semiconductor substrate; supporting the diaphragm in space by removing the sacrifice layer by etching and forming a gap between the diaphragm and the inner surface of the insulating fixed film; and dicing the substrate on the dicing street part so that an outer periphery of the adhesive layer coincides with an outer periphery of the upper surface of the semiconductor substrate, and an outer periphery of the protective film coincides with the outer periphery of the adhesive layer. forming the diaphragm inside a sacrifice layer deposited on the upper surface of the semiconductor substrate; forming, by etching the sacrifice layer, a space shaping portion having a shape of an inner surface of the insulating fixed film, and a thick film layer on an outer side of the space shaping portion separated from the space shaping portion; subsequently forming an adhesive layer on an outer side of the thick film layer so as to cover a dicing street part of the upper surface of the semiconductor substrate by the adhesive layer wherein the adhesive layer is thinner than the thick film layer; forming the insulating fixed film on the space shaping portion and covering the thick film layer and the adhesive layer with a protective film made from a material identical to the insulating fixed film; forming the back chamber in the semiconductor substrate; supporting the diaphragm in space by removing the sacrifice layer by etching and forming a gap between the diaphragm and the inner surface of the insulating fixed film; and dicing the substrate on the dicing street part so that an outer periphery of the adhesive layer coincides with an outer periphery of the upper surface of the semiconductor substrate, and an outer periphery of the protective film coincides with the outer periphery of the adhesive layer.