A semiconductor device for improving performance of a p-channel transistor and an n-channel transistor having multi-finger structures. Gates of the n-channel transistor are arranged so that their gate width direction is parallel to one side of a first region. Gates of the p-channel transistor are arranged so that their gate width direction extends at an angle of 45 degrees with respect to one side of a second region. The ratio of a maximum gate width of the p-channel transistor arranged in the second region to the pitch between the gates of the p-channel transistor is set in accordance with the ratio of the area of an ineffective region to the area of the second region.