Unemployment dropped by 84,075 people to 3.08 million, the lowest number of people out of work in the month of May for 10 years, the ministry said.
The number of people out of a job fell sharpest in services, where unemployment was down by 54,762 people, followed by construction (9,040), industry (8,085) and agriculture (7,864).
Spain's unemployment rate, taken from a poll of the population rather than the number of people registered as out of work, is the second highest in the European Union after Greece, and was 14.7pc in the first quarter.
In seasonally adjusted terms, unemployment dropped by 20,073 people, the data showed.
The number of workers paying in to the social security system rose 1.1pc , or 211,752 people, from a month earlier to 19.44 million people, the second-highest level on record, the ministry said.