An acoustic sensor is provided for improving shock resistance performance, along with a method for manufacturing the acoustic sensor. In the acoustic sensor, a fixing plate is provided by a semiconductor manufacturing process, a frame wall has a curved shape in at least a portion of the periphery of the fixing plate, the frame wall being coupled to the semiconductor substrate. A sacrifice layer removed from the inner side of the fixing plate in the manufacturing process remains at least on a portion of the inner side of the frame wall. Roughness of the remaining sacrifice layer is smaller than roughness of a sound shape reflecting structure in which a shape similar to the external shape of sound holes is repeated. Roughness of the sound shape reflecting structure is formed when removing the sacrifice layer using etching liquid supplied from the plurality of sound holes in the semiconductor manufacturing process.