Semiconductor devices may have a first semiconductor element including first active regions that are doped with a first conductivity-type impurity and that are on a semiconductor substrate, a first gate structure between the first active regions, and first contacts connected to the first active regions, respectively; and a second semiconductor element including second active regions that are doped with a second conductivity-type impurity different from the first conductivity-type impurity and that are on the semiconductor substrate, a second gate structure between the second active regions, and second contacts connected to the second active regions, respectively, and having a second length greater than a first length of each of the first contacts in a first direction parallel to an upper surface of the semiconductor substrate.