||Recently, airborne time-domain electromagnetic (ATEM) methods are gaining popularity for applications in mining, geotechnical, and environmental problems due to their efficiency in covering vast areas. To interpret ATEM data, 1D methods are commonly used because of their efficiency in handling large scale data. However, 1D methods yield an erroneous resistivity model when their basic assumptions are violated. In this study, we developed 3D inversion algorithm for ATEM data which is based on inverse Fourier transformation of frequency-domain responses and sensitivity. To efficient calculation of the multisource response and sensitivity, an edge-based finite element method with the direct solver is adopted. In addition, to reduce time for calculating sensitivity, a moving footprint approach was also used. In numerical experiment with simple 3D model containing conductive targets, subsurface model was successfully reconstructed.