A semiconductor device includes a substrate including an active pattern, a channel pattern and a source/drain pattern on the active pattern, a gate electrode provided on the channel pattern and extended in a first direction, and an active contact coupled to the source/drain pattern. The active contact includes a buried portion buried in the source/drain pattern and a contact portion on the buried portion. The buried portion includes an expansion portion provided in a lower portion of the source/drain pattern and a vertical extension portion connecting the contact portion to the expansion portion.