PURPOSE: To improve daze preventing effect and to make instruments thin, by forming a transparent plate, which is provided in front of an object that is visually observed by the human eyes, by many curved surfaces or slant surfaces so that at least the cross section on the front side of the plate forms a saw- tooth shape, as a continuous unitary body.

CONSTITUTION: A transparent plate 8 is arranged in front of an instrument 2, which is mounted in an instrument panel 1. Many curved surfaces, which are inclined upward and forward, are formed in a unitary body in the transparent plate 8. At this time, the curved surfaces are not especially required. Flat slant surfaces, whose angles can reflect light into the part outside the field of view, can be used. Thus the transparent plate 8 can be attached in parallel with a dial 3. A thickness (w) of the transparent plate 8, which occupies a part of the instrument, can be greatly reduced in comparison with a conventional instrument. The surface reflection from the transparent plate 8 is guided to the absorbing surface of a hood 5 comprising a light absorbing surface, e.g., a black material. Then the reflected image is not cumbersome at all, the daze preventing effect is improved and the instrument can be made thin.