Abstract: The extraction of intact, representative fluid samples in well-defined depths, such as from wells sunk into the ground, has until now been very difficult, and in many cases impossible to perform. A method is provided as well as a sample extractor for the extraction of intact fluid samples, in particular from a well (26) sunk into the ground, by submersion of a compressible hollow flexible body (22) fitted in a supporting device which, subsequent to submersion to the sample extraction depth, is acted upon to effect liquid entry through an inlet. In particular, hollow flexible body (22) is held in the support device in the form of a pressure vessel (2) and fully compressed by pressurized gas inside the pressure vessel, whereupon the pressure vessel is caused to change in such a way that a surrounding fluid seeps into the hollow flexible body (22), whereupon the vessel (2) with the body (22) containing the fluid sample is hoisted out of the well (26).