To enhance a visual stereoscopic effect of a carved part, in terms of an optical plate display unit which causes the optically decorative effect of the carved part by applying light from an end surface of a plate where a pattern, a character, etc. are carved, so as to scatter the light in the carved part.

An unnecessary part is shaved off in the range of a depth from the backside of the plate 10 to a first step shown by a dotted line 70. Next, an unnecessary part is shaved off in the range of a depth from the first step shown by the dotted line 70 to a second step shown by a dotted line 80. Sequentially as below, an unnecessary part is shaved off in the range of a depth from the second step shown by the dotted line 80 to a third step shown by a dotted line 90, and an unnecessary part is shaved off in the range of a depth from the third step shown by the dotted line 90 to a fourth step shown by a dotted line 100. A rounded part and an acute-angle part are formed in a staircase pattern depending on contents to be expressed, and the light is applied from the end surface of the plate 10.