Molecular sensing of target molecules is performed by using an electrode for molecular sensing in which detecting molecules which can shift a surface potential of the electrode by an interaction with the target molecules are bound directly or via coupling molecules to surface hydroxyl groups on a conductive metal oxide. By this molecular sensing, specific target molecules can be detected selectively and stably with high accuracy. It is also possible to detect an enantiomer selectively and stably with high accuracy. The present invention can provide a chemical sensing system which is useful in fields such as medicines, environments and foods.