This is the oldest site museum of the Archaeological Survey of India. In order to preserve the antiquities found from this site, a decision was taken in 1904 by the Government to construct a site museum adjacent to the excavated site at Sarnath. The building was completed in 1910 to house, display and study the antiquities. The building forms half of a monastery (Sangharama) in plan. There are five galleries and two verandahs. The antiquities in the museum are datable from 3rd century BC to 12th century AD.
The galleries have been christened on the basis of their contents, the northern most gallery is Tathagata while next one is Triratna. The main hall is known as Shakyasimha gallery and adjacent to it on south is named as Trimurti. The southern most is Ashutosh gallery, the verandahs on northern and southern side are named as Vastumandana and shilparatna respectively. Entrance to the museum is through the main hall. The Shakyasimha gallery displays the most prized collections of the museum. In the centre of this gallery is the Lion Capital of the Mauryan Pillar which has become the National Emblem of India. Apart from the images of Buddha in different posture and Tara, the inscribed colossal standing images of Bodhisattva in red sand stone dedicated by Bhikshu Bala, octagonal shaft, umbrella are also exhibited. Triratna gallery exhibits the images of Buddhist deities and some associated objects. A standing image of siddhakavira which is a form of Manjusri, standing Tara, leopgraph, seated Bodhisattva Padmapani, stele depicting miracle of Sravasti, Jambhala alongwith vasudhara, depiction of Ramgrama stupa being protected by Nagas, Inscriptions of Kumardevi, stele depicting Astamahasthana (eight great places) related to Buddha’s life, Sunga railings are of considerable eminence.
Tathagata gallery displays images of Buddha in different attitude, Vajrasattva, Bodhisattva padmapani, Nilakantha Lokesvara with a cup of poison, maitreya, preaching Buddha the most notable sculpture of Sarnath School of art. Trimurti gallery contains pot bellied seated Yaksha figure, image of Trimurti (Brahama, Vishnu and Mahesh) Surya, Saraswati, Mahisasur mardini and some secular objects like figures of birds, animals, male and female heads as well as some stucco figures. Ashutosh gallery exhibits Brahmanical deities like Shiva in different forms, Vishnu, Ganesh, Kartikeya, Agni, Parvati, Navagrahas, Bhairava and a colossal Andhakasuravadha (killing of demon Andhaka) by Shiva. Mostly architectural members are on display at two verandahs of the museum. A large lintel depicting story of shantivadina Jataka is a beautiful piece of Art.