A medical apparatus has an insertion unit inserted in the body cavity of the living body. A position/posture detecting unit detects at least one of the position and the posture of the insertion unit. Magnetic field generating units are arranged in an axisymmetrical manner on the substantially plane, and includes at least three electromagnets having magnetizing directions substantially orthogonal to the plane. A magnetic field control unit controls a magnetic field generated by the magnetic field generating unit. A position/posture varying unit varies a relative position/posture between the magnetic field generating unit and the insertion unit in accordance with position and posture information of the insertion unit obtained by the position/posture detecting unit. The magnetic field control unit controls the magnetic field generated by the magnetic field generating unit that is applied to a magnetic field operated unit arranged to the insertion unit, thereby guiding the medical apparatus.
