PURPOSE: To obtain a fuel feeding nozzle equipped with durability, and at the same time, make it possible to shorten waiting time until oil type decision by a method wherein a gas sensor, for which an ultrasonic transducer is stored in a chamber, for which a gas flow-in port is provided at one end of a cylindrical shaped container, and a through hole to be connected to a gas suction means is provided on the other end, is equipped on a fuel feeding nozzle.

CONSTITUTION: When negative pressure is added to a chamber 4 by removing a nozzle 1 from a fuel feeding device and operating a gas suction means, vapor in an automobile tank enters the chamber 4 from a vapor suction port 9 through a vapor suction pipe 8. At this point, a timing signal is generated, and pulse state ultrasonic beams are emitted from an ultrasonic transducer 5. The ultrasonic beams are transmitted through air in the chamber 4 by sonic velocity which is determined by the atmosphere (gasoline, light oil) in the automobile tank, and are reflected by the wall surface of a sealing section 6, and return to the transducer 5 again, and output an echo signal. That is, by a period of time from the time of a timing signal to the time when the echo signal is received, the component is decided.