A medical apparatus (1; 10) comprising: a distal end portion provided at a distal end of an insertion portion that has functions of performing inspection, treatment or observation; a bending portion (6; 41) connected to the distal end portion and being configured by connecting a plurality of bending pieces (21, 21f, 21r) so as to bend in two or more directions; a bending portion operation unit provided in an operation section connected to a proximal end of the insertion portion that is configured to cause the bending portion (6; 41) to perform a bending operation; a built-in component (12a; 58) in the insertion portion that extends from the distal end portion toward the operation section; a neutral position restoring elastic member (26; 50) that includes a first end and a second end and is configured to generate elasticity for causing the bending portion (6; 41) to return to a neutral position, the neutral position restoring elastic member (26; 50) being provided with a hole extending from the first end of the neutral position restoring elastic member (26; 50) to the second end of the neutral position restoring elastic member (26; 50), the built-in component (12a; 58) being inserted into the hole; a first fixing ring for integrally fixing a first end of the neutral position restoring elastic member (26; 50) to a first bending piece (21f; 43), the first fixing ring including an outer circumferential ring fixed to an inner circumferential face of the first bending piece, an inner circumferential ring that fixes the first end of the neutral position restoring elastic member (26; 50), and a support portion that fixes the inner circumferential ring to the outer circumferential ring such that the inner circumferential ring is provided in the outer circumferential ring; and a second fixing ring for integrally fixing a second end of the neutral position restoring elastic member (26; 50) to a second bending piece (21r; 47), the second fixing ring including an outer circumferential ring fixed to an inner circumferential face of the second bending piece, an inner circumferential ring that fixes the second end of the neutral position restoring elastic member (26; 50) in the outer circumferential ring, and a support portion, one end of the support portion being integrally fixed to an inner surface of the outer circumferential ring and another end of the support portion being integrally fixed to an outer circumferential face of the inner circumferential ring, wherein the ends of the neutral position restoring elastic member (26; 50) are arranged in inner holes of the inner circumferential ring of the fixing rings such that the neutral position restoring elastic member (26; 50) is disposed along the central axis of the bending portion (6; 41). a distal end portion provided at a distal end of an insertion portion that has functions of performing inspection, treatment or observation; a bending portion (6; 41) connected to the distal end portion and being configured by connecting a plurality of bending pieces (21, 21f, 21r) so as to bend in two or more directions; a bending portion operation unit provided in an operation section connected to a proximal end of the insertion portion that is configured to cause the bending portion (6; 41) to perform a bending operation; a built-in component (12a; 58) in the insertion portion that extends from the distal end portion toward the operation section; a neutral position restoring elastic member (26; 50) that includes a first end and a second end and is configured to generate elasticity for causing the bending portion (6; 41) to return to a neutral position, the neutral position restoring elastic member (26; 50) being provided with a hole extending from the first end of the neutral position restoring elastic member (26; 50) to the second end of the neutral position restoring elastic member (26; 50), the built-in component (12a; 58) being inserted into the hole; a first fixing ring for integrally fixing a first end of the neutral position restoring elastic member (26; 50) to a first bending piece (21f; 43), the first fixing ring including an outer circumferential ring fixed to an inner circumferential face of the first bending piece, an inner circumferential ring that fixes the first end of the neutral position restoring elastic member (26; 50), and a support portion that fixes the inner circumferential ring to the outer circumferential ring such that the inner circumferential ring is provided in the outer circumferential ring; and a second fixing ring for integrally fixing a second end of the neutral position restoring elastic member (26; 50) to a second bending piece (21r; 47), the second fixing ring including an outer circumferential ring fixed to an inner circumferential face of the second bending piece, an inner circumferential ring that fixes the second end of the neutral position restoring elastic member (26; 50) in the outer circumferential ring, and a support portion, one end of the support portion being integrally fixed to an inner surface of the outer circumferential ring and another end of the support portion being integrally fixed to an outer circumferential face of the inner circumferential ring, wherein the ends of the neutral position restoring elastic member (26; 50) are arranged in inner holes of the inner circumferential ring of the fixing rings such that the neutral position restoring elastic member (26; 50) is disposed along the central axis of the bending portion (6; 41).