A No campaign document entitled The Facts You Need states that an independent Scotland would be the 45th richest country in the world, behind Pakistan and Finland, compared with the UK which is sixth.
Mr Swinney said Westminster politicians “are deliberately talking down the Scottish economy”.
He called on the No campaign “to withdraw its ludicrous claim that Pakistan is richer than Scotland”, publishing “10 key strengths” of the Scottish economy over and above North Sea oil.
They include the £13 billion food and drink sector, £6 billion tourism industry, 20% of Europe’s fish, £15 billion in manufacturing, £1.9 billion life sciences sector, £5 billion in creative industries, the most top universities per head in the world, a £3.6 billion ICT sector and inward investment at a 16 year high.
Better Together said all of these successes have come “because we are part of the UK, not in spite of it”.
Mr Swinney said: ”A Yes vote is the greatest opportunity we will ever have to ensure the vast wealth of Scotland benefits all the people who live here.
”Industry estimates of up to 24 billion barrels of oil still to come represent a huge bonus but the No campaign act as if this massive windfall means Scotland has been visited by some dreadful curse.
”In fact without a single penny in revenue from the North Sea, the amount of tax we generate from our economy is, in the words of the UK Government ‘roughly the same’ per head as the UK as a whole.
”Even without oil revenue Scotland is a strong and diverse economy with the potential to generate a more secure future and greater job opportunities.
”For decades the Westminster parties have down-played the strength of our economy and now they are reduced to distortion with their ridiculous comparisons.”
A Better Together spokesman said: “All of Scotland’s key industries - from financial services to food and drink, and from our universities to renewable energy - thrive because we are part of the UK, not in spite of it.
“Being part of the UK single market sustains hundreds of thousands of jobs in Scotland. We trade more with the rest of the UK than we do with the rest of the world combined, with barrier free access to a market of 63 million people in the UK. Where is the sense in putting up barriers between Scottish firms and their customers based elsewhere in the UK?
“Until the nationalists come clean with their Plan B on currency nobody will believe a word they have to say about Scotland’s economy.”