Unemployment dropped by 63,805 people to 3.02 million, the lowest number of people registered as out of work since November 2008, the ministry said.
The number of workers paying in to the social security system rose to a record high of 19.52 million people, up 0.39%, or 75,594 people, from a month earlier, the ministry said.
The number of people out of a job fell sharpest in services, where unemployment was down by 51,752 people, followed by industry (5,808) then construction (4,066), while the number of people out of work rose in agriculture by 5,815.
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 14.7% in the first quarter.
In seasonally adjusted terms, unemployment rose by 8,986 people, the data showed.