Provided are a semiconductor device. The semiconductor device includes an SRAM cell including a first pull-up transistor, a first pull-down transistor and a first pass transistor formed on a substrate, a first read buffer transistor connected to gate terminals of the first pull-up transistor and the first pull-down transistor, and a second read buffer transistor which shares a drain terminal with the first read buffer transistor, wherein the first read buffer transistor includes a first channel pattern extending in a first direction vertical to an upper surface of the substrate, a first gate electrode which covers a part of the first channel pattern, and a first drain pattern which does not contact the first gate electrode, and which extends in the first direction, and which is connected to the first channel pattern.