An endoscope comprising: an insertion portion suitable to be inserted into a subject; an active bending portion provided in the insertion portion and bendable according to a bending operation of an operator, the active bending portion comprising a plurality of bending pieces arranged adjacently to each other in an insertion direction of the insertion portion which are pivotably connected to each other via two first mutually opposed rotation shafts in upward and downward directions and pivotably connected via two second mutually opposed rotation shafts at positions differing by 90° from the first rotation shafts in a circumferential direction of the bending pieces in leftward and rightward directions; and a passive bending portion provided closer to a proximal end side in the insertion direction than the active bending portion in the insertion portion and not bendable according to a bending operation of the operator but passively bendable when an external force is applied to the passive bending portion, the passive bending portion comprising a plurality of bending pieces arranged adjacently to each other in the insertion direction which are pivotably connected to each other by a plurality of rotation shafts, characterized in that the passive bending portion has a configuration in which the bending pieces adjacent to each other in the insertion direction are pivotably connected together via two third mutually opposed rotation shafts located coaxially with the first rotation shafts in the insertion direction, pivotably connected together via two fourth mutually opposed rotation shafts located at positions differing by 60° from the third rotation shafts in the circumferential direction and pivotably connected together via two fifth mutually opposed rotation shafts located at positions differing by 60° from the third rotation shafts and the fourth rotation shafts in the circumferential direction. an insertion portion suitable to be inserted into a subject; an active bending portion provided in the insertion portion and bendable according to a bending operation of an operator, the active bending portion comprising a plurality of bending pieces arranged adjacently to each other in an insertion direction of the insertion portion which are pivotably connected to each other via two first mutually opposed rotation shafts in upward and downward directions and pivotably connected via two second mutually opposed rotation shafts at positions differing by 90° from the first rotation shafts in a circumferential direction of the bending pieces in leftward and rightward directions; and a passive bending portion provided closer to a proximal end side in the insertion direction than the active bending portion in the insertion portion and not bendable according to a bending operation of the operator but passively bendable when an external force is applied to the passive bending portion, the passive bending portion comprising a plurality of bending pieces arranged adjacently to each other in the insertion direction which are pivotably connected to each other by a plurality of rotation shafts, characterized in that the passive bending portion has a configuration in which the bending pieces adjacent to each other in the insertion direction are pivotably connected together via two third mutually opposed rotation shafts located coaxially with the first rotation shafts in the insertion direction, pivotably connected together via two fourth mutually opposed rotation shafts located at positions differing by 60° from the third rotation shafts in the circumferential direction and pivotably connected together via two fifth mutually opposed rotation shafts located at positions differing by 60° from the third rotation shafts and the fourth rotation shafts in the circumferential direction.