Governor P Sathasivam administered the oath of office to Justice Bhushan, who was serving as acting chief justice of the high court since August last, at a function in the Raj Bhavan.
Chief Minister Oommen Chandy, along with some of his cabinet colleagues, was present on the occasion.
Justice Bhushan, hailing from Uttar Pradesh, was enrolled as an advocate with the Bar Council of Uttar Pradesh in April, 1979.
Thereafter, he practiced on civil and original side in Allahabad High Court till his appointment as judge.
He had also worked as standing counsel of Allahabad University, State Mineral Development Corporation Limited and several municipal boards, banks and education institutions.
Elevated as permanent Judge of the Allahabad High court on on April 24, 2001, Bhushan has also served as Chairman, Higher Judicial Service Committee and headed several other committees.
He was transfered to Kerala High Court and sworn in as a judge on July 10, 2014, and took charge as Acting Chief Justice the next month.