PURPOSE: To obtain an odor sensor, wherein a sensor part is suspended and excellently fixed and the heat generated in a sensor element is dissipated without passing a base stage and without adverse effects on other circuits.

CONSTITUTION: An odor sensor has a sensor part S and a base stage 2. The sensor part S comprises an element substrate 1, a sensor element 3 on the element substrate 1, a heating part for heating the sensor element 3 and two or more planar electrodes 4 provided on the element substrate 1. In the base stage 2, a plurality of planar conducting parts for the output of the sensor element 3 and the current conduction to the heating part are arranged around the element substrate 1. The sensor part S and the base stage 2 have the approximately same thickness. The electrodes 4 and the conducting part on the base stage are connected through conducting wires 5 and 5'. The sensor part S is suspended and fixed with the conducting wires 5 and 5' without contact with the base plate 2.