David de Gea has joined Manchester United on a five-year contract after the English champions confirmed they had reached agreement with Spanish side Atletico Madrid for the transfer of the goalkeeper on Wednesday.
The 20-year-old passed a medical this week, having become a European Championship winner with Spain Under-21s last weekend.
He now has the responsibility of succeeding Edwin van der Sar as United's new number one following the veteran Dutchman's retirement last month.
Although no fee was disclosed, reports suggest United may have paid as much as £18 million ($28.9m) for de Gea, pushing manager Sir Alex Ferguson's pre-season spending to about £50 million after Phil Jones and Ashley Young both arrived at Old Trafford earlier this month.
"I feel very proud and I can't wait to start playing here," said de Gea in an interview with MUTV, United's in-house television station.
"When a club the size of Manchester United comes in for you it obviously makes you very, very happy.
"I saw their interest as an extra motivation to work even harder to show off my ability.
"It's a great privilege to be part of a club like United and I'm keen to do my best and show what I can do."
Germany's Manuel Neuer, who impressed against United in the Champions League, was also talked of as a potential successor to van der Sar before opting to join Bayern Munich from Schalke 04.
Given Anders Lindegaard joined United in December, Tomasz Kuszczak may now be allowed to leave the Red Devils even though the Polish goalkeeper was on the bench for the Champions League final defeat by Barcelona at Wembley last month.
Meanwhile, de Gea's arrival may not signal the end of United's pre-season spending, with a midfielder possibly on his way to Old Trafford following the retirement of Paul Scholes.
Tottenham's Luka Modric and Alexis Sanchez of Udinese have both been linked with moves to United, who won a record 19th English championship last season, as has Inter Milan star Wesley Sneijder.