A simple method to generate a standard partial pressure p s by using various gas species has been developed for in-situ calibration of IGs and QMSs. Generating p s requires both introducing a test gas with known flow rate Q and estimating the effective pumping speed S of the high vacuum pump. The former is realized by introducing a test gas through a standard conductance element (SCE) with a molecular flow condition up to the upstream pressure of 10 4 Pa. The latter is measured by the conductance modulation (CM) method using a gate valve with an orifice. Combination of these two techniques, namely SCE–CM method, enables us to generate p s at the pressure of lower than 10 −2 Pa typically for various gas species. Four hot cathode ionization gauges, a spinning rotor gauge (SRG), and two quadrupole mass spectrometers are calibrated by SCE–CM method using 15 gases (H 2 , He, CH 4 , H 2 O, Ne, CO, N 2 , C 2 H 4 , C 2 H 6 , O 2 , Ar, C 3 H 6 , CO 2 , N 2 O, and C 3 H 8 ) from 10 −6 Pa to 10 −2 Pa. The obtained results are consistent with those of previous studies.