An aerodynamic device for a vehicle that can effectively adjust airflow within a wheel house is obtained. A fixed aerodynamic stabilizer device 10 is formed at a vehicle body longitudinal direction rear side of a rotational axis of a front wheel 15 within a wheel house 16, as a step having an airflow collision groove wall that faces downward in a vehicle body vertical direction. This fixed aerodynamic stabilizer device 10 suppresses flowing-in, into the wheel house 16, of airflow F that is generated accompanying the front wheel 15 rotating in a direction of arrow R.