There is provided a three-valued logic function circuit capable of remarkably reducing the kinds of basic circuits necessary for realizing all 33^2=19683 kinds of two-variable three-valued logic function circuits, remarkably reducing asymmetry of the switching time, and improving an operation speed and symmetry of waveform of the logic function circuit. In a three-valued logic function circuit, three transfer gates T1, T2, and T3 are turned on or off by one-variable three-valued logic function circuits C1, D1, C3 and D3, according to three logic values −1, 0, and 1 constituting a first input a, to select outputs of three one-variable three-valued logic function circuits B1, B2, and B3 connected to a second input b. The transfer gate T2 is configured by parallel connection of a switch pair of serial connection of two n-type MOS transistors and a switch pair of serial connection of two p-type MOS transistors.