Differential field effect transistors with double gate metal for integrated humidity sensors have been fabricated and the drain current drift characteristics to relative humidity have been investigated. The aspect ratio was 250/50 for both transistors to get the current difference between the sensing device and non-sensing one. The normalized drain current of the fabricated humidity sensitive field effect transistors increases from 0.12 to 0.3, as relative humidity increases from 30 % to 90 %.