Abstract: A logic circuit capable of suppressing occurrence of wraparound of signals, capable of reducing power consumption, and in addition achieving a reduction of a circuit scale and an improvement of an operating speed and a full adder using the same, wherein provision is made of an exclusive-OR generation circuit 12 for receiving a first logic signal A and a second logic signal B taking a logic “1” or “0” and generating the exclusive-OR of the first logic signal A and the second logic signal B, a dual signal generation circuit 11 for receiving the first logic signal A and the second logic signal B and generating the dual signal of the exclusive-OR of the first logic signal A and the second logic signal B, and an interpolation circuit 13 for compulsorily setting the output level of the dual signal at the level of the logic “1” when the output level of the exclusive-OR is the logic “0”, while compulsorily setting the output level of the exclusive-OR at the level of the