Abstract: A cell arrangement evaluating method for predicting a wiring density based on only a cell arranging result prior to initiation of any wiring programs so as to easily perform wiring condition evaluation based on the wiring density within a short time. Two cells to be connected by wiring are selected, and a rectangular region is obtained in which the pins of the two cells to be connected are diagonal verfexes. The probability of wiring between the pins to be connected passing through a certain grid point of wiring grid is calculated. A proportion of the rectangular region occupying each evaluation unit grid is calculated, and then, for each evaluation unit grid, an index for an increase of a wiring density made by the factor of the wiring in the evaluation unit grid is calculated. Then, for each evaluation unit grid, the sum of indexes calculated for all the wiring lines among the cells as a wiring density in the evaluation unit grid is calculated.