In an imaging apparatus for diagnosis, on an occasion when redisplaying visualized multiple cross-sectional images, the present invention is addressed to make it possible for a user to easily recognize which positions in the axial direction the cross-sectional images belong to. An imaging apparatus for diagnosis relating to the present invention constructs multiple cross-sectional images in an axial direction inside the body cavity based on line data generated by radially operating a transmitting and receiving unit, in which the apparatus is characterized by including receiving means receiving a count value from a reference position of the transmitting and receiving unit； means (602) storing the count value and the line data by being correlated with each other； means (604) constructing a longitudinal-sectional image by aligning the line data based on the count value； means (315) displaying the longitudinal-sectional image； and means (603) reading out line data correlated with the same count value as that of the line data disposed at the position appointed by the user on the displayed longitudinal-sectional image and reconstructing the cross-sectional image.
