To efficiently transmit impact from the front to a floor tunnel by providing a reinforcing rod which extends from the rear end part of a first impact absorbing member arranged in the vicinity of the rear side of an engine within an engine room within the floor tunnel and joining the inner wall surface of the floor tunnel.

When an engine room 11 compresses and deforms by a head-on collision of a vehicle, an engine 12 and a transmission 13 move to the sides of a dash panel 17 and a floor tunnel 15 and the rear end of the transmission 13 collides with a first impact absorbing member 14. Force moving backward is applied to a front tunnel reinforcing member 10 by load at this time. Because the reinforcing rod 16 is difficult to compress and deform because it is joined to the inner wall surface of the floor tunnel 15, the honeycomb structure of the first impact absorbing member 14 compresses and deforms and absorbs collision energy. Because the reinforcing rod 16 does not compress and deform, the flat plate on the side of the rear surface of the honeycomb structure does not hit the dash panel 17 and impact load can be efficiently transmitted to the floor tunnel 15.