A rare copy of a Superman #1 comic book that sold on newsstands for a dime in 1939 was purchased for $2.6 million in an auction.

The comic showing Superman leaping over tall buildings on the cover was sold Thursday night to a buyer who wishes to maintain a secret identity, according to ComicConnect.com, an online auction and consignment company.

The seller, Mark Michaelson, bought the comic in 1979 from its original owner and kept it in a temperature-controlled safe. Michaelson, now semi-retired and living in Houston, paid his way through college by buying and selling comics.

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The character created by writer Jerry Siegel and artist Joe Shuster is a pioneer of the superhero genre, and comics featuring the Man of Steel have netted super prices recently. ComicConnect announced in April that a copy of Action Comics #1, the comic that introduced Superman in 1938, sold for $3.25 million.

“Now you look at the comic books and you go ‘superheroes everywhere.’ You look back in the ’30s, there was no such thing. So this was literally the first superhero,” said ComicConnect CEO Stephen Fishler.

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Fishler said what really makes the copy sold this week notable is that it is very difficult to find high-quality copies of Superman #1.