The World War Two cipher machine was bought at a flea market by a cryptography professor, who apparently recognised its true worth.
It was sold to an online bidder in Bucharest, Romania, on Tuesday.
Enigma machines were used to carry coded military communications during the war.
First developed in Germany in the 1920s, the codes created by the electromechanical encryption devices were eventually cracked by mathematician Alan Turing and his team at Bletchley Park.
Bucharest auction house Artmark put this particular Enigma machine on sale with a starting price of €9,000.
Cristian Gavrila, the collectible consignment manager at Artmark, told Reuters: "The collector bought it from a flea market. He's a cryptography professor and... he knew very well what he was buying."
However, the eventual sale price fell far short of the record amount for an Enigma machine at auction, after one sold at Christie's in New York for $547,500 last month.
A 100 euros typewriter has sold for 45,000 euros (£40,000; $51,500) at auction, after it was discovered it was actually a German Wehrmacht Enigma I.