A gauge on new orders rose to 16.8 from 10.5 and an employment component rose to 11.9 from 7.8.
Survey respondents' view on the coming months improved by a large margin, with the gauge of business conditions for the next six months rising to 52 from 37.4.
Read MoreFed tapers $10 billion more; economic outlook cut
The Philly Fed survey is seen as one of the first monthly indicators of the health of U.S. manufacturing leading up to the national report by the Institute for Supply Management.
Gauge of US economy gains in May
A gauge of future U.S. economic activity rose for a fourth straight month in May, an indication the economy was expanding after suffering a setback at the start of the year.
The private-sector Conference Board said on Thursday its Leading Economic Index rose 0.5 percent last month after a downwardly revised 0.3 percent increase in April.
Economists had expected the index to rise 0.6 percent in May after an initially reported 0.4 percent increase in April.
"May's increase in the LEI, the fourth consecutive one, was broad-based," Conference Board economist Ataman Ozyildirim said in a statement. "Housing permits held the index back slightly but the LEI still points to an expanding economy and its pace may even pick up in the second half of the year."
The U.S. economy contracted 1.0 percent in the first quarter as a harsh winter took its toll but has shown signs of a sharp rebound in the second quarter.