The present invention relates to a sound device having a membrane attached between a case and an electro-acoustic transducer by using an adhesive foam tape, thereby enabling the prevention of a deterioration of vibration amplitude-related properties of the membrane, and the prevention of a distortion of sound that is being delivered. The sound device of the present invention is disposed on the inner side of an electronic device case having sound-transmitting holes formed thereon, so that the sound device covers the sound-transmitting holes, the sound device comprising: a waterproof air-permeable membrane which transmits air entering and exiting, and blocks water from entering an electro-acoustic transducer disposed on the inner side of the sound-transmitting holes; and a first adhesive foam tape which, in order to attach the edge of the membrane to the surrounding part of the sound-transmitting holes of the case, has one side surface thereof attached to the membrane and the other sidesurface thereof attached to the case, wherein the first adhesive foam tape has an adhesive material filled in a plurality of pores formed on adhesive surfaces of the one side and the other side adhering to the membrane and the case.