To provide an automotive horn attaching structure capable of efficiently issuing a warning sound outputted from a horn to the outside, and obtaining a sufficient sound volume and good designing freedom regarding horn attaching.

A horn 11 is disposed in the rear space of a metallic front hood 5 via a space communicated with the inner surface of the front hood 5, and the front face of the horn 11 is covered with the closed front hood 15. Thus, a warning sound generated from the horn is transmitted through the space to the front hood 5, and issued therefrom to the outside. Since the front hood 5 is made of metal, the warning sound is efficiently transmitted to the external space to obtain a sufficient sound volume.