To provide a sound insulating material for a vehicle having excellent sound insulating performance while it is embodied in a lightweight, thin wall construction, capable of being easily molded in a three-dimensional shape any as desired, and of reducing the manufacturing cost.

The sound insulating material of laminate structure consists of a sound absorbing layer 4a, an intermediate layer 3, and a sound absorbing layer 4b, wherein the intermediate layer is formed through a multi-layer inflation molding whereby hot fusion attaching films 2a and 2b consisting of thermoplastic resin film of 7-50 μ thick and having a lower melting point than a non-permeation film are adhered/laminated to/on both surfaces of the non-permeation film 1 consisting of a thermoplastic resin film of 7-50 μ thick, and the hot fusion attaching films are melted by subjecting the sound insulating material to a hot/pressure molding so that the sound absorbing layers 4a and 4b are put in fusion attachment to both the surfaces of the non-permeation film 1.