1. An information filtering apparatus comprising: means for inputting a first evaluation value of a demander for filtering; first storing means for storing a second evaluation value of a user other than said demander; means for computing a similarity between the first evaluation value inputted from said input means and the second evaluation value stored in said first storing means; means for generating a parameter based on the second evaluation value stored in said first storing means; means for estimating a suitability based on both the similarity computed by said similarity computing means and the parameter generated by said parameter generating means; second storing means for storing an evaluation item with respect to one of the first evaluation value inputted from said input means and the second evaluation value stored in said first storing means; and means for selecting the evaluation item stored in said second storing means based on the suitability estimated by said suitability estimating means, wherein said parameter generated by said parameter generating means includes a Leading-Edge degree which indicates the degree of the reliability on the evaluation value of users, wherein said first storing means stores a time at which each evaluation value is evaluated, and wherein said parameter generating means makes said Leading-Edge degree higher as the time at which each evaluation value is evaluated is earlier.