PURPOSE: To effectively use a sound effect such as a reverberation so as to prevent sound disturbance such as flutter echo by using a space on the back face side of a thin and long diffusion member made of knitted natural material and sticking a sound absorbing member on the back face.

CONSTITUTION: A sound absorbing body 1 for the interior is constructed of a diffusing member 2 formed into a semi-cylinder and a sound absorbing member 3 adhering to the back face of the diffusing member 2. The diffusing member 2 is provided with a circular arc cross section, which is provided when a cylinder is split into two, and is formed into a vertically long shape. The whole wall is covered with the sound absorbing bodies 1, in each of which the sound absorbing member 3 side serves as a mounting face, in the same way as a tile application method. Natural material is knitted and heated so as to be bent circularly, and then, the diffusing member 2 is formed. A sound colliding against the circular surface of the diffusing member 2 is not reflected in the same direction but is dispersedly reflected because of the shape of the whole diffusion member 2 or uneven shapes in respective knitted parts. A sound penetrating from gaps in the knitted parts or the joint parts in the diffusing member 2 to the back face side space 4 is damped by means of a resonance type sound absorbing structure consisting of the diffusing member 2 and its knitted parts and joint parts and is damped by means of the sound absorbing member 3 at the same time.