The invention allows an ultrasound tomographic image and an optical interference tomographic image to be created in the same position and in the same orientation with high efficiency and accuracy. For this purpose, in an imaging apparatus for diagnosis, ultrasound line data and optical interference line data oriented in a radial direction from a rotation center on the basis of a signal obtained by executing scanning are accumulated in a memory. In addition, a temporary offset line number representing a relative deviation of the ultrasound line data corresponding to the optical interference line data accumulated in the memory is calculated on the basis of a distance between an ultrasound transceiver and an optical transceiver, and a rotation velocity and a movement velocity of the imaging core during the scanning. In addition, a search start position for each of the optical interference line data and the ultrasound line data is determined on the basis of the temporary offset line number, and the search starts from the search start position to search each line data having a predetermined feature. A relative deviation of the ultrasound line data corresponding to the searched optical interference line data is calculated as a true offset line number. Then, the optical coherence cross-sectional image and the ultrasound cross-sectional image are created by relatively shifting the ultrasound line data with respect to the optical interference line data by the true offset line number and reading them.
