An introduction device for introducing an object into a vessel of a body comprises a tubular channel (15) and a dilator (11) carrying the channel. To keep the diameter of the body canal as small as possible, the wall thickness of the channel (15) is max. 0.06 mm. The channel (15) is made of a hard plastic material, such as polyamide or polyester, such that the channel (15) is not deformed by compression when the device is advanced in the body and the dilator (11) is retracted. Further, a tight fit on the dilator also prevents such compressions.