The 41-year-old, who joined the Blues from Fulham last summer, recently penned a one-year extension at Stamford Bridge.
Having made 13 appearances for Chelsea during the 2013-14 campaign, Schwarzer is eager to be involved for Jose Mourinho's side again this season.
"I'm delighted to have signed a new contract," the veteran shot-stopper told the club's official website. "I obviously wanted to stay at Chelsea.
"I really enjoyed my time here last season and it ticked a lot of boxes with some personal achievements along the way. All that was missing was winning a major trophy.
"To have the opportunity to train with and play with some world-class players, and to work with the manager who has been brilliant: it was an easy decision to re-sign here."
Chelsea play their first match of pre-season tonight when they travel to Wycombe Wanderers.