A radio tomography imaging method comprising: picking up a first calibration transmission image by using a first calibration radiation emitted from a first radiation source (24;91-1) supported by a movable gantry; picking up a second calibration transmission image by using a second calibration radiation emitted from a second radiation source (25;91-2) supported by said gantry; calculating a conversion function based on the first calibration transmission image and the second calibration transmission image; picking up a plurality of first reconfiguration transmission images by using a plurality of first reconfiguration radiations emitted from said first radiation source (24;91-1) when said first radiation source (24;91-1) is positioned at a plurality of first positions different from each other, respectively; picking up a plurality of second reconfiguration transmission images by using a plurality of second reconfiguration radiations emitted from said second radiation source (25;91-2) when said second radiation source (25;91-2) is positioned at a plurality of second positions different from each other, respectively; correcting the plurality of second reconfiguration transmission images into a plurality of corrected transmission images based on the conversion function; and reconfiguring the plurality of first reconfiguration transmission images and the plurality of corrected transmission images into three-dimensional data, wherein a position at which said second radiation source (25;91-2) is positioned when the second calibration radiation has been emitted coincides with a position at which said first radiation source (24;91-1) is positioned when the first calibration radiation has been emitted, wherein said first radiation source (24;91-1) emits a radiation when the second calibration radiation is emitted, wherein said second radiation source (25;91-2) emits a radiation when the first calibration radiation is emitted, and wherein a plurality of first times when the plurality of first reconfiguration radiations are respectively emitted coincide with a plurality of second times when the plurality of second reconfiguration radiations are emitted, respectively. picking up a first calibration transmission image by using a first calibration radiation emitted from a first radiation source (24;91-1) supported by a movable gantry; picking up a second calibration transmission image by using a second calibration radiation emitted from a second radiation source (25;91-2) supported by said gantry; calculating a conversion function based on the first calibration transmission image and the second calibration transmission image; picking up a plurality of first reconfiguration transmission images by using a plurality of first reconfiguration radiations emitted from said first radiation source (24;91-1) when said first radiation source (24;91-1) is positioned at a plurality of first positions different from each other, respectively; picking up a plurality of second reconfiguration transmission images by using a plurality of second reconfiguration radiations emitted from said second radiation source (25;91-2) when said second radiation source (25;91-2) is positioned at a plurality of second positions different from each other, respectively; correcting the plurality of second reconfiguration transmission images into a plurality of corrected transmission images based on the conversion function; and reconfiguring the plurality of first reconfiguration transmission images and the plurality of corrected transmission images into three-dimensional data, wherein a position at which said second radiation source (25;91-2) is positioned when the second calibration radiation has been emitted coincides with a position at which said first radiation source (24;91-1) is positioned when the first calibration radiation has been emitted, wherein said first radiation source (24;91-1) emits a radiation when the second calibration radiation is emitted, wherein said second radiation source (25;91-2) emits a radiation when the first calibration radiation is emitted, and wherein a plurality of first times when the plurality of first reconfiguration radiations are respectively emitted coincide with a plurality of second times when the plurality of second reconfiguration radiations are emitted, respectively.