A total 40 acres of land has been sanctioned for the proposed complex at Paharpur, about 1.5 km away.
It will be the first step to reach speedy justice to the people of north Bengal, Justice Patel said, adding the new complex will be completed in two years.
With the setting up of the circuit bench, the people of the six districts of north Bengal, specially the poor, need no longer travel to Kolkata to get justice, the Chief Minister said.
She also inaugurated a new permanent Khadya Bhawan building and the flood light of Kanchanjungha stadium.
A number of Judges of Calcutta High Court, Railway Minister Mukul Roy, state Law Minister Malay Ghatak, North Bengal Development Minister Goutam Deb, Alipurduar MLA D P Ray, Chief Secretary Samar Ghosh and Home Secretary Basudev Bandopadhyay were present at the function.