To simplify piping of a vacuum hose by disposing a vacuum tank in a space surrounded with a fender panle, an apron panel and a wheel housing.

A vacuum tank 11 is communicated with an intake manifold 17 through a vacuum hose 19. The vacuum hose 19 is passed through a hole 20 provided in an apron panel 13 and extended from an engine room 21 to a space 15. The upper end of a fender panel 12 and the upper end of an apron panel 13 are welded to each other, and the lower end of the fender panel 12 and the lower end of the apron panel 13 are respectively welded to a wheel housing 14. The upper part of the apron panel 13 is reinforced by a reinforcement bent to have a substantially U-shaped section. As a vacuum tank 11 is disposed on the intake manifold 17 side of an engine 16, it will be sufficient that the vacuum hose 19 is short that piping can be simplified.