PURPOSE: To form a wider driver's cab, by protruding the central part of a dash lower panel to the front of a car body without causing a flange or a pipe to interfere with a front wheel.

CONSTITUTION: A dash lower panel 1 is folded to a side before a car body A further secured to a front end part internal face 4a of a dash side panel 4 in a side end part of said panel 1, and a central part 1d of the panel 1, that is, the inner location in the car width direction from said part 1d providing a fixed distance from a flange 1b is protruded to the front side of the car body A so that a groove 1c housing pipes 2 can be formed in the vertical direction along the flange 1b of the panel 1. In this way, a driver's cab is formed to a wider space.