PURPOSE: To improve the light reflecting function of the inside surface of the undersurface wall of a lighting fixture body for a vehicular headlight of a so-called slant type having a front lens slanted in the forward lower part direction of the body.

CONSTITUTION: A diffusing reflection surface 10 is formed on the whole or part of the inside surface of the undersurface wall 1b of a lighting fixture body 1 formed to be continued in the forward direction of a reflector 3, and a front lens 7 for covering a front opening in the body 1 is mounted onto the body 1 in such a manner that it may be slanted in the forward lower part direction of the body 1. Out of light in a lighting chamber 8 inside the lens 7, one particularly reflected to the side of the undersurface wall 1b is diffusedly reflected and outputted in the forward upper part direction of the lens 7 by the diffusing reflection surface 10 formed on the inside surface of the undersurface wall 1b of the body 1, so that the diffused light directed in the forward upper part direction makes it to obtain visibility to a transportation information board and a traffic sign respectively arranged above a vehicular running lane.