A linked switching partial area and a non-linked switching partial area are set in at least one display area in which a tomogram is to be displayed. When an input operation giving an instruction to switch the tomogram is performed in the non-linked switching partial area, only the image displayed in the display area is switched. When the input operation is performed in the linked switching partial area, the image displayed in the display area is switched and an image displayed in each of the other display area or areas is also switched in a linked manner.
