A thin section fabrication apparatus, comprising: an epi-image data acquisition unit for providing epi-illumination, for imaging the surface of a block in which a biological sample is embedded, and for acquiring image data; a diffuse image data acquisition unit for providing diffuse illumination, for imaging a portion, which is embedded in the block, of the biological sample, and for acquiring image data; an exposed shape extraction unit configured to extract the shape of the biological sample that is exposed to a surface of the block, based on the image data acquired by the epi-image data acquisition unit; an embedded shape extraction unit configured to extract the shape of the portion, which is embedded in the block, of the biological sample, based on the image data acquired by the diffuse image data acquisition unit; a control unit configured to determine an end of a preliminary cutting by comparing the shape extracted by the exposed shape extraction unit and the shape extracted by the embedded shape extraction unit, and configured to control the operation of the preliminary cutting, characterized by: a vector calculation unit configured to obtain a center of an exposed portion of the biological sample based on the image data acquired by the epi-image data acquisition unit, configured to obtain a center of an embedded portion of the biological sample based on the image data acquired by the diffuse image data acquisition unit, and configured to calculate a direction and a magnitude of a vector from the center of the exposed portion toward the center of the embedded portion, wherein: when the magnitude of the vector calculated by the vector calculation unit is larger than a second predetermined value, the control unit is configured to control a relative posture between the block and a cutting blade based on the direction of the vector so that the vector is decreased and to perform the preliminary cutting. an epi-image data acquisition unit for providing epi-illumination, for imaging the surface of a block in which a biological sample is embedded, and for acquiring image data; for providing epi-illumination, for imaging the surface of a block in which a biological sample is embedded, and for acquiring image data; a diffuse image data acquisition unit for providing diffuse illumination, for imaging a portion, which is embedded in the block, of the biological sample, and for acquiring image data; for providing diffuse illumination, for imaging a portion, which is embedded in the block, of the biological sample, and for acquiring image data; an exposed shape extraction unit configured to extract the shape of the biological sample that is exposed to a surface of the block, based on the image data acquired by the epi-image data acquisition unit; an embedded shape extraction unit configured to extract the shape of the portion, which is embedded in the block, of the biological sample, based on the image data acquired by the diffuse image data acquisition unit; a control unit configured to determine an end of a preliminary cutting by comparing the shape extracted by the exposed shape extraction unit and the shape extracted by the embedded shape extraction unit, and configured to control the operation of the preliminary cutting, configured to determine an end of a preliminary cutting by comparing the shape extracted by the exposed shape extraction unit and the shape extracted by the embedded shape extraction unit, and configured to control the operation of the preliminary cutting, a vector calculation unit configured to obtain a center of an exposed portion of the biological sample based on the image data acquired by the epi-image data acquisition unit, configured to obtain a center of an embedded portion of the biological sample based on the image data acquired by the diffuse image data acquisition unit, and configured to calculate a direction and a magnitude of a vector from the center of the exposed portion toward the center of the embedded portion, wherein: configured to obtain a center of an exposed portion of the biological sample based on the image data acquired by the epi-image data acquisition unit, configured to obtain a center of an embedded portion of the biological sample based on the image data acquired by the diffuse image data acquisition unit, and configured to calculate a direction and a magnitude of a vector from the center of the exposed portion toward the center of the embedded portion, wherein: when the magnitude of the vector calculated by the vector calculation unit is larger than a second predetermined value, the control unit is configured to control a relative posture between the block and a cutting blade based on the direction of the vector so that the vector is decreased and to perform the preliminary cutting.