It is an object to achieve high performance of a semiconductor integrated circuit depending on not only a microfabrication technique but also another way and to achieve low power consumption of a semiconductor integrated circuit. A semiconductor device is provided in which a crystal orientation or a crystal axis of a single-crystalline semiconductor layer for a MISFET having a first conductivity type is different from that of a single-crystalline semiconductor layer for a MISFET having a second conductivity type. A crystal orientation or a crystal axis is such that mobility of carriers traveling in a channel length direction is increased in each MISFET. With such a structure, mobility of carriers flowing in a channel of a MISFET is increased, and a semiconductor integrated circuit can be operated at higher speed. Further, low voltage driving becomes possible, and low power consumption can be achieved.