According to an aspect, a testing instrument that is used for testing an airway protection function includes: a pipe portion continuous from an inlet port to an outlet port, the pipe portion having a plurality of holes penetrating the pipe portion from an outer surface of the pipe portion to an inner surface of the pipe portion, the holes being provided for guiding a reagent gas mixture to the inside of the pipe portion； and a guide portion covering all of the holes to form a closed space and guiding the reagent gas mixture to the closed space from an inflow port.
