[Aim] When the body cavity of a subject to be examined is observed by an endoscope inserted into the body cavity, a positional relationship and close proximity between a region of interest, such as a region on which a surgery is to be performed, and a treatment tool are more definitely recognized. [Solution Means] A virtual endoscope image generation unit (24) receives, as an input, a three-dimensional medical image formed by a three-dimensional medical image formation unit (5), and generates a virtual endoscope image representing the body cavity viewed from a position in the three-dimensional medical image corresponding to the position of a treatment tool detected in real time by a treatment tool position detection unit (11). The generated virtual endoscope image is displayed on a WS display (10).
