PURPOSE: To obtain an MOS semiconductor circuit where an influence due to the swinging of a voltage is small by allowing the area of an input voltage where a P-channel transistor and an N-channel transistor simultaneously go to an ON-condition and an output potential goes to be intermediate between an L and an H to be narrow.

CONSTITUTION: The source of a P-channel transistor 1 constituting a first inverter 7 is connected to a node 12 which is the drain of a P-channel transistor 3 to constitute a second inverter 8 and an N-channel transistor 4. Then, the source of an N-channel transistor 2 of the first inverter 7 is connected to a node 13 which is the drain of a P-channel transistor 5 to constitute a third inverter 9 and an N-channel transistor 6. Thus, by the influence of the second inverter 8 and the third inverter 9, since the area of an input voltage VIN where the P-channel transistor 1 of the first inverter 7 and the N-channel transistor 2 simultaneously go to the ON-condition is allowed to be narrow, the influence given to an output voltage by the fluctuating of the input voltage goes to be small.