To provide connection capable of always securing high positioning precision and rigidity of flange connection even in a case where a manufacturing tolerance of a flange element is wide.

This connection is composed of a connection surface between a spindle nose 1 of a machine tool, a changing-type tool, gauge, or a workpiece holder 7. The machine tool is provided with a shortened centering taper 8 on the lower part of a flange of the holder 7, the taper is formed as a tubular stub 15 rigid in the axial and the radial direction and elastically expandable on the circumference. The stub is fitted to the diameter of a centering taper 6 on the spindle nose 1 through elasticity.