The "Room of the ritual Implements", square in plan, was renovated already during the Roman period. In modern times, the vaulted ceiling has been reinforced with an arch that spans across the room in a east-west direction. An opening on the eastern wall, now filled in, led into an area of the building that still lies unexplored.

The pictorial repertoire on the walls of this room elaborates on well-known Dionysiac themes. Unlike the other rooms, however, the main subjects here are not animals or creatures, but ritual objects. It is still possible to discern, inside the middle panels, tenuous representations of those votive vessels and musical instruments that were generally used during rituals in honor of Dionysos. A tambourine decorated with tassles (tympanum) leaning against a staff wrapped with ivy and topped by a pine cone (thyrsus) is painted on the eastern wall. Both tympanum and thyrsus were characteristic attributes of the Menads, companions of the god Dionysos.

In the left corner of the lunette on the south wall is depicted a marine animal, which now – alas – is missing its head. Its lower body ends in a tripartite fin, similar to that of a fantastic creature or a dolphin.

The narrow space between the modern arch and the northern wall was richly decorated: it is still possible to see a thin dark line that frames a tamburine painted in yellow. Above it, there are flimsy tree branches with small green leaves within a panel outined in red paint.

The pavement is made of irregularly shaped large slabs of colored marble (giallo antico, alabastro, africano) embedded in a layer of concrete. The slabs, surely re-used, show geometric and vegetal motifs carved on their surfaces.

Two openings pierce the northern wall: one leads to the room with a staircase that takes up to the modern house; the other to a long corridor with walls covered in white stucco, now closed by the foundations of the building above it.