Dimension: Width: 13.07 meters Length: 22.20 meters Height: 15 meters Standing on the right of Ubosot, Phra Wiharn is also a brick building with two layered roof with three dividers. The building were built with Chino Thai art style, leaving out traditional Thai roof ornament such as Chofa and decorating with Chinese ceramic and plastering technique. Above the frame of the building’s gates and windows are furnished with plastering of cotton rosemallow, covered with gold leaves. All doors and windows are garnished with Lai Rod Nam (Thai Lacquer art) on the front side. The door’s Lai Rod Nam is in the form of Guardian deities of the Gate. Unlike the door, the Lai Rod Nam of each window can be divided into two sections. The top part is covered with cotton rosemallow, while the bottom half is a scene from the life of Buddha. Painting can be found behind the doors and windows of this building. The painting can be divided into three sections. The top part is painted with lotus in flowerpot. The middle painting is flower in vase, while the bottom is covered with flowerpot. Inside each door and window, paintings of lotus, fish and water can be found. Mural painting with tempera color is used to garnish the inside of the building, the ceiling with Dao Pedan (Thai ceiling decorative shape), and the cornice with Malai (Thai flower garment shape). The wall is also covered with mural painting in the shape of Chinese phoenix on red background. Paintings of S. Dhammabhakdi, an artist whom specialized in Thai Buddhist painting, are framed above each door and window. The paintings retell the life of Vessantra, a Bodhisattva prince with great compassion whom performs great deed of charity, in 13 paintings in corresponding to 13 chapters of his life.

The terrace of this building is decorated with two layers green tile in the shape of Prajam Yam (Thai decorative design) and flower shape. Chedis (Thai stupa) with the shape of Yor Mum Mai Sibsong surround the ground of Phra Viharn.