The economic and political situation in Germany after the First World War, and the Treaty of Versailles, which the German people consider humiliating, are the main reasons for the coming to power of Adolf Hitler and the National Socialists. After Hitler came to power, he and his party recovered the German economy and almost rooted out unemployment. They tried to turn Germany into a self-sustaining economy, but they did not achieve this completely. For political and economic reasons, they started a war they were not ready for. Through trade, exploitation of conquered territories, forced labor, and synthetic substitutes for materials they lacked to some extent they improved their economic situation and enabled the war to continue. With the arrival of Albert Speer as Minister of Armaments and in the position of one of the most powerful people in the country, there was a major reorganization of the German economy and increased efficiency. However, this improved organization and efficiency would be greatly undone by the deterioration of the war situation and all its negative impacts on the economy. The aim of this paper is to explain and understand the functionality, adaptation, faults and the rise and decline of the German economy in World War II.