A method to deposit haematite (Fe2O3) thin films by plasma-enhanced chemical vapour deposition (PECVD) is introduced. The sensitivity of the PECVD Fe2O3 thin films to liquified petroleum (LP) gas, coal gas, hydrogen (H-2) and ethanol (C2H5OH) is studied. The results show that films prepared in this way are highly sensitive to C2H5OH but are not as sensitive to LP gas, coal gas or H-2. Therefore the films prove to be highly selective.