We try to constrain the gas inflow and outflow rate of star-forming galaxies at z similar to 1.4 by employing a simple analytic model for the chemical evolution of galaxies. The sample is constructed based on a large near-infrared spectroscopic sample observed with SubarulFMOS. The gas-phase metallicity is measured from the [N II] lambda 6584/H alpha emission line ratio and the gas mass is derived from the extinction corrected H alpha luminosity by assuming the Kennicutt Schmidt law. We constrain the inflow and outflow rate from the least-chi(2) fittings of the observed gasmass fraction, stellar mass, and metallicity with the analytic model. The joint chi(2) fitting shows that the best-fit inflow rate is similar to 1.8 and the outflow rate is similar to 0.6 in units of star-formation rate. By applying the same analysis to the previous studies at z similar to 0 and z similar to 2.2, it is shown that both the inflow and outflow rates decrease with decreasing redshift, which implies the higher activity of gas flow process at higher redshift. The decreasing trend of the inflow rate from z similar to 2.2 to z similar to 0 agrees with that seen in previous observational works with different methods, though the absolute value is generally larger than in previous works. The outflow rate and its evolution from z similar to 2.2 to z similar to 0 obtained in this work agree well with the independent estimations in previous observational works.