The present invention relates to a routing analysis method for performing a routing analysis on an integrated circuit from a netlist which is information on a plurality of cells constituting the integrated circuit and routes connecting the cells, and the routing analysis method comprises a step (Step 1) of obtaining the sum of areas of a plurality of cells, the number of cells or the number of routes connecting the cells from the netlist, to be defined as a constant C, and calculating a layout area S which is an area of a square layout region, by dividing the constant C by a predetermined constant U, a step (Step 2) of calculating a total route length L by multiplying a half perimeter length H of the layout region having the layout area S obtained in Step 1 by a predetermined coefficient α, and a step (Step 3) of calculating a routing difficulty index by dividing the total route length L by the layout area S. Thus, the present invention provides a routing analysis method for an integrated circuit, which, allows calculation of routing difficulty index with high accuracy of prediction.