An instrument panel device includes an instrument panel incorporating a speed meter, an odometer, a main switch and a meter cover covering the instrument panel and the main switch. The main switch is provided with a key cylinder projecting inwardly from the side surface of the meter cover. An inclined surface is formed on the side surface of the meter cover so that the projecting direction of the key cylinder is oriented obliquely downwardly. The inclined surface is formed at a position lowered by one step from the outermost circumferential surface of the meter cover. The resulting configuration reduces the size of the instrument panel device by reducing the depth of the instrument panel device incorporating the main switch with the key cylinder.