PURPOSE: To deliver selectively both the attenuation quantity and frequency characteristics to both ends of the 2nd resistance by grounding an input signal via the 1st resistance, a capacitor and the 2nd resistance in series and at the same time grounding the joint of the 1st resistance and the capacitor via the 3rd resistance and a changeover switch.

CONSTITUTION: A signal source 11 is grounded via a resistance R11, a capacitor C11 and a resistance R13 in series; while the joint of the R11 and the C11 is grounded via a resistance R12 and a switch S11 in series. Then the output signals E12 are extracted from both ends of the R13. Thus it is possible to obtain an attenuator circuit which can deliver selectively both the attenuation quantity and frequency characteristics by means of the switch S11.