Noise reduction devices mainly use diffraction, interference, resonance phenomenon of sound wave. Also noise can be absorbed directly by using absorption materials. But absorption materials are effective in high frequency region. To enhance the absorption performance, absorption materials are combined with a solid structure. Recently, many ideas that solid structures are inserted inside a porous material layer have been suggested and this kind of structure is sometimes called as meta-porous layer. Also many researches apply optimization techniques to improve the performance of noise reduction devices and structures. In this research, we conducted acoustic topology optimization problem related to the layout of solid materials inside a porous material layer. As a material model of porous material, we used Delany-Bazley model and conducted acoustic analysis using finite element method in frequency domain.