The European Union's executive commission said that its economic sentiment indicator for the 12 countries sharing the euro rose to 105.3 points in April from 103.6 points in March.
The increase confounded private economists expectations for a fall to 103.0 points.
The industrial confidence component of the indicator increased to 1.0 from minus 1.0, while consumer confidence improved to minus 10.0 from minus 11.0.
Economists had forecast no change for both the industrial and consumer confidence.
Services sector confidence rose to 18.0 from 15.0, retail sentiment was unchanged at minus 1.0, and construction was flat at minus 3.0.
"The main impetus behind the rise of the sentiment indicator is the positive developments in the industry and the services sectors," the commission said.
Separately, the commission's eurozone business climate indicator also posted a sharp rise, jumping to 1.12 points -- its highest level since December 2000 -- from 0.81 points in March.
The commission said the upturn suggests "that industrial production growth should be sustained throughout the first half of this year".
It attributed the increase to marked improvements in managers' assessment of the production trend observed in recent months and of both total order books and export orders books.