A harness module structure in which a module installation section (5) is formed on the surface of a steering support member (1) extending in the substantially vehicle width direction and in which a harness module (4) is provided at the module installation section (5). The harness module (4) has a harness module body (6) and a harness module cover (11) attached to the harness module body (6). The harness module body (6) is surrounded by the harness module cover (11) and the module installation section (5). The module cover (11) has a grounding section (12) for grounding to the module installation section (5), and the harness module body (6) is supported without contact by the grounding section (12) with a gap (13) left between the harness module body (6) and the module installation section (5).
