PURPOSE: To provide a layout display device which can simplify the display of a complicated layout pattern and can shorten the time needed for display of the layout pattern.

CONSTITUTION: This layout display device is provide with an input part 1 which designates a display range, a layout database 2 which stores the layout pattern data, an editing part 3 which edits the layout pattern data in response to the display range designated by the part 1, a display part 4 which shows the editing result of the part 3 in layout, and a display control means 5 which adds the prescribed attribute data to each layer of the layout pattern data and outputs the layer information including the attribute. Then, the part 3 edits the layout pattern data corresponding to the designated display range based on the layer information including the attribute that is given from the means 5.