An insertion shape detecting probe includes shape detecting elements for generating or detecting magnetic field or magnetic; signal lines connected to the shape detecting elements; supporting members that support the shape detecting elements; inner sheaths into which the signal lines and the supporting members are inserted; and an outer sheath into which the inner sheaths, the shape detecting elements, and at least one portion of the supporting members are inserted. The inner sheaths are each formed from a multiple-lumen tube that has a first lumen formed at a substantially central portion of each inner sheath and second lumens formed around an exterior periphery portion of the first lumen, and the supporting members are elongated wire rods one portion of which is arranged along exterior peripheries of the shape detecting elements in an axial direction and other portion runs through the second lumens.