In order to eliminate a steering hanger beam and to take efficient advantage of the empty space within an instrument panel, an instrument panel construction includes a main instrument panel unit 50 which is formed with an open cross sectional shape, and which comprises a plate shaped upper surface member 51 which extends substantially in the horizontal direction of the body of the vehicle across its transverse direction, and a front surface member 52 which curves towards the passenger compartment of the vehicle from said upper surface member 51 and extends downwards substantially in the vertical direction; and in that this main instrument panel unit 50 is made as a single unit from magnesium alloy by a die casting process, and is fixed to left and right front pillars.