"What I maintain, and will always maintain, and I am convinced that justice will (demonstrate), is there has never been any money received in an irregular way," Rubiales told reporters after leaving the Madrid court.
Rubiales, 46, who resigned following global outrage after he forcibly kissed Women's World Cup star Jenni Hermoso last summer after the final, testified at length.
"I have answered all the questions I was asked, if I have to come here again I will be here, collaborating -- I am the one most interested in clearing everything up," said Rubiales.
Rubiales must appear in court every month and ask permission from the judge before making any trips outside of Spain, a court source told AFP.
Rubiales was briefly detained on his return to Spain from the Dominican Republic at the start of April as part of a probe into federation (RFEF) contracts signed since 2018, including one signed by Rubiales to take the Spanish Super Cup to Saudi Arabia.
"There has never been any irregular tender, we have been paid with the utmost excellence and in the pursuit of legality," added Rubiales.
On March 20 investigators searched Rubiales' house in the southern city of Granada among 11 locations in the alleged graft scandal.
The raids were part of "an investigation linked to presumed crimes linked with corruption in business, fraudulent administration and money laundering", according to judicial sources.
The Super Cup contracts are worth 40 million euros a year ($43.3 million) with the deal brokered by Kosmos, a company owned by former Barcelona and Spain defender Gerard Pique.
The Spanish Super Cup took place for the first time in Saudi Arabia in 2020.
It returned to Spain for a year during the Covid-19 pandemic but the subsequent three editions have returned to the oil-rich Gulf state.
New Spanish football president Pedro Rocha is also under investigation in the alleged graft case.
Rocha served as federation vice-president under Rubiales, then replaced him on an interim basis before being elected as chief this week.
Rubiales is also set to go on trial over the non-consensual kiss on Hermoso's lips, which under Spanish law can be classed as sexual assault.
