An inspection method for inspecting a specimen by repeatedly acquiring X-ray CT transmission images with an x-ray inspection apparatus, comprising: a first step of setting a position of an evaluation region in shape information representing a three-dimensional shape of the specimen, the evaluation region being set based on design information from three-dimensional CAD, information from simulation results or measurement data performed in the past; a second step of setting a grid converted evaluation region by making the evaluation region into a lattice grid so that unit lattices are larger than voxels as smallest unit configuring three-dimensional data generated by a X-ray CT transmission images and smaller than the size of the evaluation region, where the lattice grid is provided in a three dimensional shape along axis U, V, W of an orthogonal coordinate system set with regards to the specimen; a third step selecting one of a plurality a slice plane candidates by projecting the grid converted evaluation region onto planes spanned by two of the three axis of the orthogonal coordinate system; a fourth step of selecting one slice plane from the slice plane candidates (701, 702, 703) having smallest displacement when scanning the projected grid converted evaluation region in the direction of the axis spanning the slice plane; a fifth step of causing the x-ray CT inspection apparatus to repeatedly perform a partial scan on the specimen via the slices plane selected by the sliced plane selection step; a sixth step of determining non-defectiveness of the evaluation region based upon partial scans of the evaluation region and per the unit lattice; and a seventh step of executing an evaluation region update processing comprising analyzing shape information generated based on a plurality of transmission images of the specimen acquired from the partial scan, determining, based on the history of analysis results, whether an update of the evaluation region should be performed, displaying the result on a display monitor, and when the update execution of the evaluation region is permitted by an operator who has checked the determined result, performing an update of the evaluation regions by repeating the setting processing for the lattice grid according to the second step, the third step, and the fourth step. a first step of setting a position of an evaluation region in shape information representing a three-dimensional shape of the specimen, the evaluation region being set based on design information from three-dimensional CAD, information from simulation results or measurement data performed in the past; a second step of setting a grid converted evaluation region by making the evaluation region into a lattice grid so that unit lattices are larger than voxels as smallest unit configuring three-dimensional data generated by a X-ray CT transmission images and smaller than the size of the evaluation region, where the lattice grid is provided in a three dimensional shape along axis U, V, W of an orthogonal coordinate system set with regards to the specimen; a third step selecting one of a plurality a slice plane candidates by projecting the grid converted evaluation region onto planes spanned by two of the three axis of the orthogonal coordinate system; a fourth step of selecting one slice plane from the slice plane candidates (701, 702, 703) having smallest displacement when scanning the projected grid converted evaluation region in the direction of the axis spanning the slice plane; a fifth step of causing the x-ray CT inspection apparatus to repeatedly perform a partial scan on the specimen via the slices plane selected by the sliced plane selection step; a sixth step of determining non-defectiveness of the evaluation region based upon partial scans of the evaluation region and per the unit lattice; and a seventh step of executing an evaluation region update processing comprising analyzing shape information generated based on a plurality of transmission images of the specimen acquired from the partial scan, determining, based on the history of analysis results, whether an update of the evaluation region should be performed, displaying the result on a display monitor, and when the update execution of the evaluation region is permitted by an operator who has checked the determined result, performing an update of the evaluation regions by repeating the setting processing for the lattice grid according to the second step, the third step, and the fourth step.