Abstract: The invention provides sound insulation members having enhanced sound insulating properties without increasing the thickness of the sound insulation members. The object is achieved by a sound insulation member having disposed inside a pouch-shaped film 1 with a resin coating a flat sound absorption material 2 formed of foamed porous material or fiber material and having its inner space communicated, and filling a filler gas 3 having a sound impedance that differs from air. According to the present invention, since the present sound insulation member is filled with gas having sound impedance that differs from air, the present sound insulation member has superior sound insulating properties since it reflects sound on the sealed surface and also absorbs the sound by the sound absorption material disposed therein.