To reduce manufacturing cost of a soundproof wall for absorbing noises, etc. and facilitate construction by unitizing a sound absorbing panel.

A sound absorbing panel unit C, which forms the soundproof wall provided in an eaves shape on the upper portion of an existing wall surface, includes: a supporting frame 20 triangular in a lateral view, which comprises a horizontal frame 22 for placing the sound absorbing panel 3, and a vertical frame 21 and a diagonal frame 23 for being attached to a support 30 of the erected soundproof wall 1; a pair of angle bars 40 which respectively are stretched over the pair of horizontal frames 22 of the supporting frame 20 in the longitudinal direction near their ends; and a plurality of sound absorbing panels 3 with a predetermined thickness, which are placed on the pair of angle bars 40 and made of flat plate-like porous cement-based material.