Abstract: The apparatus for supporting an investment decision making is provided with profit model editing section which creates or modifies a profit model which shows a relationship between any parameter and cash flow; data set editing section which creates and modified a data set including values of the parameter; a case saving section which saves a case where a profit model is associated with one or plural data sets; and an analysis processing section which performs various analysis processings of a working case comprising the profit model of the case which has been saved by the case saving unit and the one data set or one of the plurality of data sets as the minimum unit of simulation.