An apparatus for determining a received signal level of a radio wave in a ray-tracing wave propagation environment includes a reception unit configured to receive the radio wave; and an analyzing unit configured to determine the received signal level of the radio wave in the ray-tracing wave propagation environment. Further, the analyzing unit is configured to analyze a correlation of the height and altitude of a surface roughness that recognizes the surface of a surrounding obstacle depending on the length of wavelength in the course of delivery of a received signal of the radio wave and analyze precisely the scattering of the received signal depending on the surface roughness to determine the received signal level of the radio wave when determining the received signal level.