The party, which is close to Greece's Syriza, has faced questions over the source of its funds since Spanish media reported last month that one of its founders was paid a six-figure sum by leftist Latin American nations for consulting work.
Podemos, founded in January 2014, had revenues of €947,081 ($1,071,520) last year, party officials told a news conference.
The bulk of the funds, 82.9 percent, came from donations from supporters. Another 9.7 percent come from subsidies while 7.3 percent came from the sale of merchandising such as T-shirts.
The average amount of a donation was €14.79.
"The doubts over the origins of the financing of Podemos have been erased," Podemos co-founder and chief political analyst Carolina Bescansa told the news conference.
The release of the party's accounts comes a week after another founder, Juan Carlos Monedero a former adviser to late Venezuelan president Hugo Chavez, appeared before the press to address questions over his income from consulting work.
He said he earned €425,000 in 2013 from a development bank belonging to the Bolivarian Alliance bloc, or ALBA, a grouping of mostly left-wing Latin American and Caribbean countries including Venezuela, to develop a proposal for a single Latin American currency.
Monedero said "not a single euro" went to Podemos, adding he was the victim of a "witchhunt" ahead of a year-end general election.
He added that the money went to a firm he created called "Caja de Resistencia" and was used to fund a political talk show hosted by Podemos leader Pablo Iglesias that was broadcast over the Internet and on cable.
Podemos, which rallies against corruption and economic inequality, also said it financed its campaign for the European elections in May with donations from around 5,000 supporters.
The party said its campaign cost €137,196.
Podemos stunned Spain's political establishment by winning five seats in the European Parliament.
Recent surveys show it is favoured by about one-fourth of the electorate — ahead of all rivals in some polls and slightly trailing the ruling conservative Popular Party in others.
"It is possible to launch a political project with little revenue and only the support of citizens," said Bescansa, a sociology professor who is an expert in designing and analysing opinion polls.
"Podemos is not financed with money from banks, other governments, or big companies or big donors," she added.
Podemos published the income statements of all of its leaders and its five European lawmakers on the internet.
Local and regional elections are slated for most of the rest of the country in May with a general election to be held at a yet-to-be determined date at the end of the year.