There is disclosed a method of correcting a design pattern considering a process margin between layers of a semiconductor integrated circuit, including calculating a first pattern shape corresponding to a processed pattern shape of a first layer based on a first design pattern, calculating a second pattern shape corresponding to a processed pattern shape of a second layer based on a second design pattern, calculating a third pattern shape using a Boolean operation between the first and second pattern shapes, determining whether or not an evaluation value obtained from the third pattern shape satisfies a predetermined value, and correcting at least one of the first and second design patterns if it is determined that the evaluation value does not satisfy the predetermined value.