"I have exhausted politics and want to dedicate more time to my family," Barak, who has held his post since 2007, said in a nationally broadcast speech from his Tel Aviv headquarters. "There are many ways to contribute to the state, not only through politics,"
Barak, who was prime minister from 1999 to 2001, said he will stay on as defense minister until a new government is formed after national elections Jan. 22, 2013.
He said he had a difficult time making the decision.
"I feel exhausted dealing with political life, which has never been a passion of mine, and I feel there is room to allow other people to serve in senior roles in Israel," he said.