An insulator dash (20) installed on the interior side surface side of a dash panel (10), comprising a single sound absorbing layer (21) formed of a fiber assembly or a laminated assembly having light and soft skin layers (22,23,26,27,28) laminated on the surface of sound absorbing layer (21), wherein, since the reflected noise reflected from the inner surface of an instrument panel (40) is taken again from the front surface side into the sound absorbing layer (21) for sound absorption in addition to the sound absorbing and shielding performance of the insulator dash (20), the sound absorbing performance in the instrument panel (40) can be increased, whereby the weight can be reduced and a rise of sound pressure in the instrument panel (40) can be abolishing a conventional sound shielding layer so as to increase a silentness in a cabin.