To provide an analog arithmetic circuit which can keep a small phase difference between the input and output despite the high frequency and has the satisfactory high frequency characteristic by applying an input signal to a 1st input terminal of a differential amplifier and applying an input converted signal obtained by converting the input signal via a coefficient circuit to a 2nd input terminal of the differential amplifier.

This arithmetic circuit comprises a differential amplifier circuit 1 which includes the transistors Tr1 and Tr2, the resistances R1 and R2 and a constant current source I0 and a coefficient circuit 2 which converts an input signal. In the circuit 1, the input voltage Vi is inputted to the base terminal of the Tr1 and the voltage Vi1 obtained by converting the input voltage via the circuit 2 is inputted to the base terminal of the Tr2, respectively. The emitter terminals of the Tr1 and Tr2 are connected to the source I0. The output voltage V0 is taken out of the collector terminal of the Tr2, Then the conversion coefficient α1 of the circuit 2 is changed to change the output voltage V0.