The Deputy First Minister said she has assured the other airports, particularly Glasgow, that ministers would remain neutral over which gets support.
She told the Scottish Parliament Infrastructure Committee the Government wants to return the Ayrshire airport to profit then sell it to a private operator, but that could take years.
She added: "We aim to ensure it has no impact on 'team Scotland' airports. We will operate in a neutral way in terms of route development. It is important to give that assurance to other airports, particularly Glasgow, being the closest."
She said when support is given there will be no special treatment for Prestwick.
The Government has already spent £3 million at Prestwick and will put in £2m in the next financial year. A report is due next month on the airport's business strategy.
Ms Sturgeon said land at the airport is under-used and there is more scope for income from shops.
She said there were no plans to change the name of the airport to Robert Burns International, despite a local campaign, but added: "The focus has to be on what has the best chance of returning the airport to profit.
"If there is evidence that calling it Robert Burns International will help do that or will make it harder we will look at it. We have not ruled it out."