The present invention relates to an analytic methods and an analysis apparatus, are used for respiration gas, method and apparatus, can accurately analyze the biogas for being included in breathing gas by breathing only once, can pass through the respiratory diseases of the biogas of analysis one patient of monitoring. For this purpose, the analytic method for respiration gas includes: a detecting step, a kind of respiration by being included in breathing gas is detected by a biosensor according to the disease of a patient, and detect the peak velocity and humidity for the breathing gas that biogas generates The the first detected value aligning step for obtaining the detected value of a correction, by being removed from the probe value detected by corresponding biosensor, the effect of peak velocity and humidity on corresponding biosensor The the second detected value aligning step for obtaining a gas corrected value, by removing the effect of the biogas in addition to corresponding biogas from the detected value for the correction for being calculated as corresponding biogas, on corresponding biosensor A concentration calculation step of the concentration of corresponding biogas is calculated by using gas corrected value.
