In this paper, we examined the distribution of sound pressure level of the air layer of the dry double floor using the finite element method. Impact source was used the impact force characteristics (1) of JIS A 1418-2. Distribution of sound pressure level of the floor of the air layer was under the influence of the vibration characteristics of the slab. Air layer under the floor was considered measurement point, and is compressed by bending wave of the slab around the measurement point.
