PURPOSE: To smoothly bend a tube without flattening or crushing a tube by the light weight and inexpensive spacer and to protect the part.

CONSTITUTION: An inserting part 1 is composed of a bar like member having the flexibility, a tube bending spacer A formed with a recessed groove 11 along the longitudinal direction on the surface of the inserting part 1 is used, the inserting part 1 is inserted into a tube 3, after bending the tube 3 in a required shape while being inserted, and a grip part 2 of the spacer A is gripped and drawn from the tube 3.