To reduce noise which enters sealed space from its front, back, left, or right, through clearance and resonance mode in the front and back directions, by widely covering a dash panel with a bulkhead at inclined direction of a vehicle and surrounding each of left and right parts of the dash panel with each individual space.

A first bulkhead 7, a second bulkhead 8, a third bulkhead 9, and a fourth bulkhead 10 are provided on the left and right sides of an engine room E from a strut tower 2 to a dash panel 5. Because a dash panel 5 is widely covered with the second bulkhead 9 placed in the inclined direction of a vehicle and each of left and right parts of the dash panel is surrounded with individual space in this structure, noise which enters into sealed space from its front, back, left, or right, through clearance is reduced. In addition, noise level in the backward space of the fourth bulkhead 10 is reduced, and therefore, insulation characteristic of sound which reaches from an engine surface to ears of an occupant is improved.