A tritium gas monitor was developed by applying several techniques including pulse shape analysis. The optimum analyzer values were determined for parameters such as the bias (voltage) applied to the detector, counting gas flow rate, and mixing ratio of sample air to counting gas using an enclosed tritium reference source. After applying these optimized parameters, the factor for converting counting rate to tritium concentration was determined by conducting an experiment using tritiated methane gas. Finally, the detection limit of the monitor for air samples containing tritium was determined based on the conversion factor.