Planar field effect transistor nanodevices were fabricated based on individual InAs nanowires. The electrical performance of the devices was measured and studied in vacuum, air, N2, O2, H2O and pollutant in air, NO2. Compared with the performance in vacuum, the performance of the device in air changes, e.g. the threshold voltage of the device (VT) shifts to positive direction, the off-state current (Ioff) increases and the on-off ratio (Ion/Ioff) decreases in air. The main air component, N2, does not have distinguishable impact on the performance of the device. The effect of O2 is very weak. H2O increases Ioff, decreases Ion/Ioff and shifts VT negatively. The component of the pollutant in air, NO2 is found to bring a positive shift of VT, and an unchanged Ion/Ioff.