Kim Hyok Chol, a 43-year-old former advisor at North Korea's foreign ministry, was one of 17 new ambassadors who presented their credentials to the king at the Zarzuela Palace.
King Juan Carlos also received the credentials of new UK ambassador to Spain Simon Manley.
North Korea opened its first ever embassy in Spain in October 2013, a story that The Local broke.
At the time Spain's foreign ministry said North Korea's "interest in opening an embassy in Madrid follows its policy of having a more direct dialogue with the main nations of the European Union."
North Korea has an embassy in nine other EU member states: Austria, Britain, Bulgaria, the Czech Republic, Germany, Italy, Poland, Romania and Sweden.
The country's embassy in Madrid will have between 10-15 employees once it is fully up and running, an embassy spokesman said.
Spain and North Korea have had diplomatic relations since February 2001.
North Korea's Deputy Minister of Foreign Affairs, Kung Sok Ung, visited Spain last year as part of a tour of several EU states.
But the secretive Asian nation has had an unofficial ambassador in Spain for some time now: Alejandro Cao de Benós.
This quirky Spaniard's admiration and loyalty to North Korea landed him the job of "Honourary Special Delegate" for Cultural Relations with Foreign Countries.