The insertion system (10) has an insertion device (20) and a posture detection region, and is built in the insertion device (20), and at least a first rotation change amount and a first direction change amount of the posture detection region are included. And one or more posture detection units (100) capable of detecting one of them. The insertion system (10) is a posture calculation unit that calculates posture information of the insertion device (20) based on at least one of the first rotation change amount and the first direction change amount detected by the posture detection unit (100). (70).挿入システム（１０）は、挿入装置（２０）と、姿勢検出領域を有し、挿入装置（２０）に内蔵されており、姿勢検出領域の第１回転変化量と第１方向変化量との少なくとも一方を検出可能な１以上の姿勢検出部（１００）とを有する。挿入システム（１０）は、姿勢検出部（１００）によって検出された第１回転変化量と第１方向変化量との少なくとも一方を基に、挿入装置（２０）の姿勢情報を演算する姿勢演算部（７０）とを有する。
