Markit Economics said the manufacturing sector's Purchasing Managers Index for the month rose from 51 in October to 52.4, "signaling the strongest improvement in U.S. manufacturing business conditions for five months."
The PMI shows business expansion with numbers above 50.
In the component indexes that make up the diffuse PMI, new order growth and output rose to five-month highs, while the employment index posted its sharpest gain since July.
Markit called the improvement "modest."
"This is an encouraging sign that the slowdown in the goods-producing sector may have bottomed-out," said Markit Chief Economist Chris Williamson.
"Manufacturing therefore looks likely to make a positive contribution to economic growth in the fourth quarter after acting as a slight drag in the third quarter," he said.
For November, the index for new orders rose from 51.1 to 52.8. The production index, also known as output, rose from 51.4 to 52.9.
The employment index rose from 51.8 to 52.6.
A flash index is based on incomplete data, meaning the figures could be revised in the final report.