A medical apparatus includes an endoscopic insertion portion provided with an image pickup unit and a channel; a treatment unit provided with a sensor and a bending portion and passed through a channel, with a distal end portion of the treatment unit being allowed to protrude from an insertion-portion distal end portion of the endoscopic insertion portion, where the sensor is disposed in the distal end portion and the bending portion is adapted to bend the distal end portion; a storage unit adapted to store three-dimensional image data; a target position setting unit adapted to set the target position based on the three-dimensional image data; a virtual endoscopic image generating unit adapted to generate a virtual endoscopic image using a line-of-sight parameter which includes a position, a direction, and a roll angle of the distal end portion detected by the sensor, based on the three-dimensional image data; and an image processing unit adapted to perform a superimposition process and thereby display operation information used to insert the distal end portion to the target position in superimposition on the virtual endoscopic image.