PROBLEM TO BE SOLVED : To provide a rent predictor, etc., capable of precisely predicting a future rent to be obtained from a real estate such as an apartment.SOLUTION : A prediction method for rent has a coefficient for a multiple regression model carrying out weighing of respective factors for information regarding a real estate used for calculating the rent when the real estate is rented stored to a rent model table. The prediction value for future rent obtained from the real estate is calculated by application of the coefficient stored to the rent model table to the respective factors for the information regarding the real estate when an input of information regarding the real estate which is to be the subject for calculation of the rent is received. In order to reflect the change in the rent due to the passage of years, although a prescribed coefficient may be applied as the passage of years, a more precise rent prediction is made capable by storing a combination of different coefficients for every passed year to the rent model table and applying the coefficient according to the passage of years.