Examination of the measurement of air volume capacity values by non-invasive methods carried out previously does not allow to know more specifically the value contained in the lungs. For this reason, a spirometer device is needed to determine the function of the airway and the capacity of the air in a person's lungs. This tool is designed using the MPXV7002DP gas pressure sensor which will be applied to calculate the forced vital capacity of the lungs through a flow sensor in the mouthpiece, ATMega32 IC, and LCD 4x20 character as the measurement media viewer. The first test method with the use of BTL brand spirometer calibration tube capacity, obtained an error of 0.36% then the module was used to test the forced vital capacity (FVC) of the lungs in 20 people consisting of 9 people with medical record of normal lung, 6 people with pulmonary asthma, 5 people are smokers. Based on the measurement of forced vital capacity values that is compared between the research module and the BTL Spirometer, the fluctuated measurement data were obtained, it happens because of in the every measurement, the breath is given by volunteers at the time can be different. After going through of the process comparison tools and data analysis, the highest error was 1.77% and the lowest error was 0.13%. It is not exceeding the standard error set from manual BTL brand spirometer book of 2%.