Amy Leong, previously with Nasdaq-listed FormFactor, is taking over from Chandra Nair with effect from July.
Leong's appointment follows "many months" of search.
In its note on May 31, DBS, which warns of some "near term volatility" of the share price, points out that this is the third change in the company's C-suite.
AEM had previously changed its CFO and COO - all within the past year.
See also: Grab obtains LTA licence to operate taxis in Singapore
"The change in CEO may not be well received by the market," says DBS, which has nonetheless maintained its "hold" call and $1.75 target price.