PURPOSE: To attain miniaturization and high speed of a comparator circuit at the same time by using a comparison input of the comparator circuit having no serial input so as to connect the comparator circuits in series.

CONSTITUTION: Suppose that a high-order 7-bit of data A, B, that is, all inputs to input terminals P1∼P7, Q1∼Q7 of the comparator circuit 11 satisfies the condition of Pi=Qi, an H level signal is fed to an input terminal P0 of the comparator circuit 1 when the low-order 4-bit of the input data A, B, that is, values of input terminals A0∼A3, B0∼B3 of a comparator circuit 12 has a relation of A>B, and a signal of H level is fed to an input terminal Q0 when A<B. Thus, when the H level signal is fed to the input terminal P0, the comparator circuit 11 discriminates as P=Q, and a signal of A=B is outputted as the comparision output (P=Q), and when the H level signal is fed to the input terminal Q0, it is discriminated as P>Q and a signal of A>B is outputted as the comparison output (P>Q).