A gas concentration distribution measuring apparatus includes a gas detection part, a gas detector position information measuring part, and a gas concentration distribution display unit. The detection part includes gas detectors provided at mutually different positions to measure a concentration of a predetermined gas, and moves while maintaining relative positions of the detectors. The position information measuring part measures position information of the detectors of the detection part. And, measured values of gas concentrations measured by the detectors of the detection part and position information of the detectors measured by the position information measuring part when the detectors finish measurement of gas concentrations are inputted in the display unit, then the display unit displays a distribution of concentrations of the predetermined gas in a space in which the detection part moves, based on the measured values of the gas concentrations and the position information of the detectors.