TOKYO — Parliament elected Yasuo Fukuda to be Japan’s prime minister today, thrusting the moderate political insider into the job of taking on a resurgent opposition and rebuilding the scandal-scarred ruling party.

Mr. Fukuda immediately named a Cabinet that overlapped considerably with the lineup of his predecessor, Shinzo Abe, in an apparent bid to limit disruption following Mr. Abe’s shock resignation earlier this month.

In his first news conference, Mr. Fukuda vowed to push for extension of Japan’s naval mission in support of American-led forces in Afghanistan, clear up a scandal over the loss of millions of pension records, and regain the public’s trust in politics.

“Japan’s naval mission is invaluable to the international community,” Mr. Fukuda said. “We will push to secure an extention at the earliest possible time.”

As a measure of the troubles that await Mr. Fukuda, parliament split over his election — the first time since 1998 the chambers have diverged in the decision to choose a prime minister — with the lower house supporting him but the upper house choosing an opposition leader. Under parliamentary rules, the lower house decision triumphed.

Mr. Fukuda, 71, took over from Mr. Abe, a nationalist who lasted barely a year in office after damaging scandals and the ruling Liberal Democratic Party’s loss in upper house elections in July discredited him and his party.

The first son of a prime minister to take the post, Mr. Fukuda acknowledged the difficulties ahead, calling for the kind of discipline he had to enforce as chief Cabinet secretary from 2000 to 2004.

“The situation surrounding the LDP is very severe, and we face difficulty in keeping the government under control without cooperation from all party members,” Mr. Fukuda told reporters after the election.

Mr. Fukuda has pledged to keep Japan as a strong American ally in the fight against terrorism, improve relations with Asia, and provide assistance to rural areas left behind in Japan’s economic recovery. He also faces mounting calls by the opposition to call snap elections for the lower house, where the LDP rules.

Mr. Fukuda’s Cabinet lineup included just two new faces compared with Mr. Abe’s previous Cabinet: Defense Minister Shigeru Ishiba Ishiba and Education Minister Kisaburo Tokai.

Mr. Fukuda inherits a political landscape left in tumult by Mr. Abe’s troubled leadership.

Mr. Abe stunned the nation when he announced September 12 that he wanted to quit, and checked into a hospital the following day for unspecified stress-related abdominal complaints.

“I want to extend my apologies to the people for not being able to complete my duties,” Mr. Abe said today in a statement.

Though popular at the outset of his term, Mr. Abe’s public approval ratings had fallen to about 30%. Four Cabinet ministers resigned in money-related scandals, and an agriculture minister committed suicide in May.

A final blow came when he led the LDP to elections in July in which they lost control of the upper house to the opposition.

Mr. Fukuda, whose father Takeo Fukuda was prime minister from 1976 to 1978, is known as a steady, experienced hand in political negotiations. He had to resign as Cabinet secretary in 2004 after saying he had unwittingly skipped payments to the national pension system.