If you are asking about the economics of Nazi Germany, then this has come up fairly frequently and garnered some excellent responses. I've put them together in a new FAQ section: Nazi Economics.

The executive summary is that Germany's economy during the 1930s was not sustainable and was not intended to be. Hitler's government poured massive amounts of money into wartime preparation in the form of military, infrastructure, and heavy industry spending accruing debts that were temporarily staved off by seizing the cash supplies in Austria and Czechoslovakia, and then by going to war. Hitler also artificially buoyed the economy, particularly the ethnically German male economy, by seizing Jewish assets and banning both them and women from major sections of the workforce. Yet at the same time the Nazis cracked down on unions and used wage and price controls to get the most out of their deficit spending.

You'll see Tooze's Wages of Destruction recommended several times in the past answers, because it really is the go-to book on the subject.