Semiconductor device for performing an error check operation

A semiconductor device includes an error detection circuit configured to generate fixed data by fixing any one of a first group and a second group included in internal data to a preset level based on a burst chop signal and an internal command address in response to a read command, and generate an error detection signal by detecting an error of the fixed data; and a data output circuit configured to generate latch data by latching the internal data based on a first latch output control signal, and generate output data by serializing the latch data and the error detection signal based on a second latch output control signal.