Diyawadana Nilame has the custody of key of Silver casket of seven caskets. He is the lay custodian of the sacred tooth relic. This position is recorded in the Dathuwansa, The chronicle of tooth relic, as Dhathurakkadikari. Diyawada Nilame also bears the responsibility of organizing daily poojas and annual festivals. Responsibilities of assets and properties of Maligawa and the regulation of duties of others. Officials in the service of sacred tooth relic are also entrusted to him. He is also duty bound to welcome foreign diplomats and other local and foreign delegations.
The official costume of Diyawadana Nilame is the upcountry ceremonial dress. The dress is tailored use in 12 Yards of material for each item. Called Thuppottiya, Pachchawadama, Somaniya and Kawaniya, and 43 Yards all together. The dress consists of 14 parts. In terms of the tradition, for Kumbal Perahara, the dress of Nilame appears in white, while for Randoli Perahara, either golden or some other popper color is used. The costume is itched using golden thread.