Congress senior leader Oommen Chandy was sworn in on Wednesday as the 21st chief minister of Kerala representing the United Democratic Front (UDF) here.
He was administered the oath of office and secrecy at the Raj Bhavan by Governor RS Gavai around 2 pm.
Six other ministers also took oath.
Chandy on Sunday was elected the legislative party leader of Congress party in the state unanimously after Ramesh Chennithala, the president of Kerala Pradesh Congress Committee, said he is not in the race to be the chief minister, paving the way for Chandy to be the CM uncontested.
Oommen Chandy was elected for the 10th consecutive time from his seat Puthupally in Kottayam district.
Congress-led UDF formed the government in Kerala after they defeated the LDF (Left Democratic Front), led by the Communist Party of India-Marxist (CPI-M) by a narrow margin of two seats.
While UDF got 72 seats, LDF finished close with 68 in the 140 member Kerala assembly