A sulfide gas concentration measuring device comprises: an exhaled breath collection tool to be put to a subject to introduce exhaled breath of the subject into the exhaled breath collection tool； a pressure regulator comprising an inlet port connected to the exhaled breath collection tool； a sulfide gas sensor connected to an outlet port of the pressure regulator to measure a concentration of sulfide gas in the exhaled breath discharged from the outlet port； and a pressure measuring device. The pressure measuring device is configured to measure a pressure in the inlet port of the pressure regulator to make the subject aware of the measured pressure.
