Route searching method and storage medium thereof

A route of a signal from a starting point pin to an end point pin is searched for in an electronic circuit designed by combining cells which are basic devices entered for use in a designing process. At this time, one or more conditions satisfied by a route to be distinguished from other routes from the starting point pin to the end point pin are set. A route can be distinguished from others depending on whether or not the route satisfies the set condition, and a search for a route from the starting point pin to the end point pin is carried out on each route to be distinguished from others by a condition.