The reflective display device of the invention includes: a display layer; an
optical element placed on an observer side of the display layer; and a reflection
element placed on a side of the display layer opposite to the observer side. The
optical element has a principal plane including a plurality of tilt faces tilted
with respect to the display plane. Light incident on the display layer through
the optical element and reflected by the reflection element is allowed to outgo
in a direction roughly normal to the display plane.