The Apple executive in charge of hardware engineering for the iPhone, iPad and other Apple products is retiring from the company, Apple said Thursday.
Cook called Mansfield an "instrumental part" of Apple's executive team but asserted that the engineering team would "not miss a beat" during the transition to a new leader.
"We are very sad to have him leave and hope he enjoys every day of his retirement," Cook said in the statement.
Mansfield joined Apple in 1999 when it bought Silicon Graphics spin-off Raycer Graphics. He has led hardware engineering for the Mac since 2005, for the iPhone and the iPod since 2010, and for the iPad since its inception, Apple said.
He is less well-known than some other Apple executives, such as designer Jonathan Ive or marketing chief Phil Schiller, but he appeared in a few Apple promotional videos, including this one for a new line of MacBooks.
His departure will follow that of Chris Weeldreyer, a user interface design manager who left Apple this month after eight years to become a design manager at Facebook.
Mansfield was hired by Apple not long after Steve Jobs returned to the company and was made CEO in the late 1990s. He worked with Jobs throughout the past decade when Apple introduced a string of breakthrough products that helped to redefined the cellphone and the personal computer.
Apple's stock performed well during that time, and two years ago Mansfield reportedly sold Apple shares worth more than $10 million.
A certain amount of attrition among senior managers was inevitable following Jobs' death last October, said industry analyst Roger Kay of Endpoint Technologies.
"While Jobs was there, there was this sense of anticipation and excitement, of being part of a once-in-a-generation type experience. It's easy to imagine that after his death it could become a bit anticlimactic."
"I would call this normal post-Jobs-ean attrition," he said.
Still, it is not an insignificant departure. Mansfield will be replaced by Dan Riccio, a vice president in charge of iPad hardware engineering who reports to Mansfield. Riccio joined Apple shortly before Mansfield did, in 1998.