His contract had been due to expire after Euro 2012, which runs from June 8 to July 1 in Poland and the Ukraine.
"I've renewed my contract as coach. I've renewed my contract with the federation," Del Bosque told the Onda Cero radio station, without providing further details.
The former Real Madrid coach, who led Spain to glory at the 2010 World Cup in South Africa, did not disclose the length of his new contract but contracts with the Spanish Football Federation tend to have durations of two years.
Spain will begin their Euro 2012 campaign as favourites to retain the trophy they won in Austria and Switzerland in 2008, but Del Bosque said: "I don't subscribe to the theory that not winning the Euro would be a failure."
He said he was "very optimistic" about the return to fitness of Barcelona striker David Villa, who fractured his left tibia during the FIFA Club World Cup in December.
Del Bosque, who became Spain coach in July 2008, will announce his squad for Euro 2012 on May 15.
Spain were drawn in Group C, alongside Italy, Croatia and the Republic of Ireland.
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