Facebook Italia said it had "cooperated fully".
The Italian-registered company, according to its official document, has social capital of 10,000 euros ($13,000) and 11 employees and therefore pays very low taxes, Italian media reported.
Facebook Italia had gross revenues of 2.0 million euros in 2011, which counted as "services" for promotion on the Italian market.
A probe by Italian tax police against Google Italy last month found that the company failed to declare income of 240 million euros ($310 million) and pay value added tax of 96 million euros.