Abstract A new method for localization of an odor source is proposed. A probe with four anemometric sensors and four gas sensors has been developed so that the direction of an odor source can be determined. The anemometric sensors are used for measuring the direction of the air flow carrying odor molecules, and the gas sensors are used for detecting the gas-concentration gradient. Moreover, mounting the probe on a mobile stage with the probe under the control of a personal computer makes it possible to realize an autonomous mobile sensing system. An odor source has been successfully localized using this system in a wind tunnel.