A radio wave propagation simulator for simulating a state of propagation of a radio wave within a radio service area, characterized by: an input section (17, 20) for receiving the measured data of a received power density ratio within a band in said radio service area and an amount of noise generated in a measuring instrument for measuring the received power density ratio within a band, a processor section that is adapted to: store measured data of said received power density ratio within a band and said amount of noise of said measuring instrument in a storage device; calculate a value of the received signal code power of a desired signal; modify radio parameter settings of said radio base station on the basis of the calculated value of the received signal code power of a desired signal and an amount of noise of said measuring instrument; calculate total received power within said radio service area and the received power density ratio within a band before and after the modification of the radio parameter settings of said radio base station; calculate a relative value on the basis of the difference between the calculated values of the received power density ratio within a band before and after the modification of the radio parameter settings wherein said relative value refers to an amount improved by said modification of the radio parameter settings; and estimate the received power density ratio within a band after the modification of the radio parameter settings by adding said relative value to the measured data of said received power density ratio within that band; and an output section that supplies as an output the processed results made by said processor section. an input section (17, 20) for receiving the measured data of a received power density ratio within a band in said radio service area and an amount of noise generated in a measuring instrument for measuring the received power density ratio within a band, a processor section that is adapted to: store measured data of said received power density ratio within a band and said amount of noise of said measuring instrument in a storage device; calculate a value of the received signal code power of a desired signal; modify radio parameter settings of said radio base station on the basis of the calculated value of the received signal code power of a desired signal and an amount of noise of said measuring instrument; calculate total received power within said radio service area and the received power density ratio within a band before and after the modification of the radio parameter settings of said radio base station; calculate a relative value on the basis of the difference between the calculated values of the received power density ratio within a band before and after the modification of the radio parameter settings wherein said relative value refers to an amount improved by said modification of the radio parameter settings; and estimate the received power density ratio within a band after the modification of the radio parameter settings by adding said relative value to the measured data of said received power density ratio within that band; and store measured data of said received power density ratio within a band and said amount of noise of said measuring instrument in a storage device; calculate a value of the received signal code power of a desired signal; modify radio parameter settings of said radio base station on the basis of the calculated value of the received signal code power of a desired signal and an amount of noise of said measuring instrument; calculate total received power within said radio service area and the received power density ratio within a band before and after the modification of the radio parameter settings of said radio base station; calculate a relative value on the basis of the difference between the calculated values of the received power density ratio within a band before and after the modification of the radio parameter settings wherein said relative value refers to an amount improved by said modification of the radio parameter settings; and estimate the received power density ratio within a band after the modification of the radio parameter settings by adding said relative value to the measured data of said received power density ratio within that band; and an output section that supplies as an output the processed results made by said processor section.