The present invention provides a semiconductor circuit capable of effectively applying a filter function to both of L-level noise superimposed during originally H signal periods and H-level noise superimposed during originally L signal periods. An input signal branches off into two and one of them is inputted through signal inverting means to a first delay circuit including a first capacitor. The other is inputted to a second delay circuit including a second capacitor. An output signal from the first delay circuit and an output signal from the second delay circuit are inputted to separate input terminals of a flip-flop.