Marcello Di Finizio was swiftly arrested by the Vatican gendarmerie yesterday and, according to Italian media, received treatment for a leg injury incurred when he climbed up on to the dome on Friday.
"It was really cold and I was dead tired," he wrote shortly afterwards on his Facebook page.
Di Finizio, who owns a cafe in the northeastern city of Trieste according to reports, had earlier posted a message saying "they have taken everything from me, but they won't take my dignity as well".
During his latest exploit he unfurled a banner reading: "Help us Pope Francis."
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He called on the Italian government to end austerity measures, with the country suffering from record unemployment.
"Stop in the name of God, you are killing us all. Give us back our lives," he said in another Facebook message.
Suicides linked to the economic crisis make headlines in Italy, where hundreds of thousands of businesses have been forced to close.
The unemployment rate among 15 to 24-year-olds rose to a record 42.4 per cent.
On Friday, Italy's borrowing costs fell in the latest sign of improved investor confidence in the economy but Italians are still suffering tax hikes and other austerity measures imposed as the eurozone debt crisis gripped the country.
Italian Prime Minister Matteo Renzi has promised to reboot the economy by reducing taxes, slashing the costs of Italy's bureaucracy and promoting businesses.