A virtual endoscopic image generating unit for generating, from a 3D medical image representing an interior of a body cavity of a subject formed by a 3D medical image forming unit and inputted thereto, a virtual endoscopic image, in which a position of a structure of interest identified by a position of interest identifying unit is a view point of the virtual endoscopic image, a real-time position of at least one of an endoscope and a surgical tool detected by an endoscope position detecting unit or a surgical tool position detecting unit is contained in a field of view of the virtual endoscopic image, and the position of at least one of the endoscope and the surgical tool is shown in an identifiable manner in the virtual endoscopic image, is provided. A display control unit causes a WS display to display the generated virtual endoscopic image.
