Atom interferometer (AI) uses the wave character of atoms and measure the difference in phase between atomic matter waves along different paths. The field of AI has expanded rapidly in recent years, and have many uses in fundamental physics including measurements of G, the fine-structure constant, the universality of free fall, and gravitational waves. They also have applied uses as accelerometers, rotation sensors, and gravity gradiometers. Applying methods from atomic, molecular, and optical physics, we advance experimental technology to push the sensitivity of AI as inertial sensors to new levels. We work for a movable and robust atomic inertial sensor, and in future wish to apply it on high precision gradiometer aided navigation.