In an endoscope system including a plurality of endoscopes 2 including insertion portions 10 having different diameters, each of the plurality of endoscopes 2 includes a first bending portion 7 subjected to bending operation to actively bend, a second bending portion 8 passively bent by external force, a flexible tube portion 9 having rigidity higher than rigidity of the second bending portion 8, and a bending portion 30 including the first bending portion 7 and the second bending portion 8. In the plurality of endoscopes 2, a relation among lengths of the second bending portions 8 is set to be contrary to a size relation among insertion portion 10 diameters. 挿入部１０の径が異なる複数の内視鏡２を具備する内視鏡システムであって、複数の内視鏡２のそれぞれが、湾曲操作されて能動的に湾曲する第１湾曲部７と、外力により受動的に湾曲する第２湾曲部８と、該第２湾曲部８よりも剛性が高い可撓管部９と、第１湾曲部７および第２湾曲部８を有する湾曲部３０と、を備え、複数の内視鏡２は、挿入部１０径の大小関係に対して第２湾曲部８の長さの関係が相反するように設定されている内視鏡システム。
