A semiconductor device includes an output driver having a variable current driving ability, for outputting an amplified data signal to the outside through a transmission line; a nonvolatile memory having a specific area for storing output adjustment data to adjust the current driving ability of the output driver; an output adjustment data readout unit for reading out the output adjustment data from the specific area of the memory in response to powering on; and a current driving ability adjustment unit for adjusting the current driving ability of the output driver on the basis of the output adjustment data read out from the memory.