PURPOSE: To provide a fluid leakage stopping mechanism for stopping the leakage of fluid having ignitability without using electricity and a semiconductor producing apparatus using the same.

CONSTITUTION: This mechanism consists of a treating section 16 which is supplied with an ignitable gas 11 and subjects a semiconductor wafer 15 to a film formation treatment, a gas supplying section 12 which supplies the ignitable gas 11 to this treating section 16 and a piping 13 which connects this gas supplying section 12 to the treating section 16 and is provided with a shielding member 14 consisting of a shape memory alloy in its internal part 13a. This shielding member 14 is heated by leaking out and igniting of the ignitable gas 11 and is deformed to the shape to shut off the flow of the ignitable gas 11 in the internal part 13a of the piping 13, by which the leaking of the ignitable gas 11 is automatically stopped and extinguished.