The number of people infected also rose, although health emergency chief Fernando Simon said this was due to increased testing and that most concerned people with mild or no symptoms.
Spain has been one of the countries worst hit by the global epidemic but it has tentatively started to ease a lockdown imposed on March 14.
The health ministry said on Thursday the total number of fatalities rose to 19,130 over the past 24 hours as 551 people died from COVID-19, the disease caused by the virus, up from 523 the previous day. The overall number of cases of those infected rose to 182,816, from 177,633 on Wednesday.
"The increase in the number of tests has led to an increase in the number of cases," Simon said at the government's daily news conference.
However, Catalonia's health department announced late on Wednesday an additional 3,242 coronavirus deaths since the start of the pandemic, nearly doubling its previous tally to 7,097 for the region.
The addition was due to a methodology change, with data from funerary services on suspected and confirmed coronavirus deaths in nursing homes and private homes included for the first time.
Until now, the Catalan health department was only reporting coronavirus deaths in hospitals and confirmed by tests.