There is provided a semiconductor device including a wafer and a focus monitoring pattern formed on the wafer. The focus monitoring pattern having at least one pair of first and second patterns, and the first pattern has an unexposed region surrounded by an exposed region, and the second pattern has an exposed region surrounded by an unexposed region. In addition, the present invention provides a method of fabricating a semiconductor device comprising the steps of forming at least one pair of first and second patterns on a wafer, the first pattern having an unexposed region surrounded by an exposed region, the second pattern having an exposed region surrounded by an unexposed region, and checking a focusing condition on exposure by measuring widths of the first and second patterns formed on the wafer.