An active pattern structure may include a substrate including an active pattern array defined by a plurality of trenches including first to third trenches, and first to third isolation patterns in the first to third trenches, respectively. The active pattern array may include a plurality of first and second active patterns extending in a first direction, and the first to third trenches may be between the first and second active patterns and may include different widths from each other. The active pattern array may include an active pattern group including one of the first active patterns and one of the second active patterns sequentially arranged in a second direction substantially perpendicular to the first direction. Each of the first and second active patterns may have a minute width.