Congress leader Mateen Ahmed, who was named pro-tem speaker, administered the oath to Kejriwal.
Urban Development Minister Manish Sisodia took oath after Kejriwal. Both of them, however, left the house soon after taking oath.
The other five ministers - Rakhi Birla, Girish Soni, Satendra Jain, Saurabh Bharadwaj and Somnath Bharti - also took oath.
They were followed by other legislators.
Congress legislators looked subdued while lawmakers from the Bharatiya Janata Party drummed the table whenever their legislators stood up for the oath.
Arvinder Singh Lovely of the Congress was the lone legislator who took oath in English while Nand Kishore Garg and Naresh Gaur took oath in Sanskrit.
Anil Jha took oath in Maithili language.
Aam Aadmi Party supporters gathered outside the main gate of the Delhi Vidhan Sabha to watch their party leaders arrive for the first assembly session.
The 28-member minority government of the AAP is to face the confidence vote Jan 2.
--IANS (Posted on 01-01-2014)