A measurement system for circuit parameters of a device under test (DUT) that reduces the number of attachments and detachments of calibration kits. An error factor acquisition device includes a first calibrator connected to ports of a network analyzer that has a first state realization unit that determines open-circuit, short-circuit, and standard load states for the ports. Second calibrators connected to the first calibrator and the DUT have a second state realization unit that determines open-circuit, short-circuit, and standard load states for the ports. The first calibrator includes first connection units that connect the ports to the first state realization unit or to the respective second calibrators, while the second calibrators respectively include a second connection unit that connects the ports to the second state realization unit or the DUT.