Germany's business climate index rose to 89.9 points in September from 88.8 points in the previous month, according to data from the ifo Institute published Thursday.
Analysts expected 89.1 points for the month.
Meanwhile, the current situation index stood at 89.5 points, against the prior 88.5 points and the consensus estimate of 89 points.
The expectations indicator increased to 90.4 points from the revised 89 points earlier, compared with the market forecast of 89.3 points.