The main deity of this temple is Lord Shiva a.k.a. Mahadeva, as the name suggests. It is believed that the huge Shivalinga here was consecrated by Lord Agni. Thus, it is believed that Lord Agni always worships Lord Shiva, and he accompanies him. Due to this belief, the idol is not carried outside for processions on rainy days.
The Sanctum of the temple is located inside the cave which is 12 feet long and 8 feet wide. In front of the sanctum, there is a Mugha mandapa, entirely carved in the rock with beautiful artistry. Although the deity looks east during Darshan, the devotees can only see the right side of the Lingam. (“Parshwa Darshan”.).The goddess Parvathi also resides there, perpetually to Lord Shiva, personifying knowledge. Lord Ganapathi's image is carved on the wall of the cave towards the west side of the sanctuary. The rock-laden soil and the Namasakara Mandapa, built from 16 pillars made of rock, present a large number of beautiful sculptures. To the north of the temple is a hall where Saraswati Pooja and Chakyar Koothu are led during Navratri and many religious events respectively.