The number of Spaniards working part time has risen noticeably during the country's economic crisis.
In 2008, 11.6 percent of employees didn't work a full week. Now that figure is 16.4 percent, or 2.75 million people, according to official Spanish figures.
But more than half of these workers would work more hours if they could, new EU numbers on various form of 'underemployment' released on Thursday show.
Some 57 percent of this group, or 1.53 million people feel they are "underemployed", the figures from Eurostat reveal. Only Greece (72 percent) and Cyprus (59 percent) have higher rates of part-time workers who want to work more.
In Germany, by contrast, 27 percent of workers are part-time but only 16 percent of those people would take on more hours if they could.
Thursday's Eurostat figures also show there are 1.1 million Spanish people aged 15 to 74 who are available for work, but not actively looking. A further 223,000 people are looking for work but not available to start immediately.
These two groups — not covered by official employment statistics — make up a labour force of 1.4 million people, Eurostat says.
Spain's official unemployment rate is currently 26 percent.