1. An automatic layout planner for laying out an object in a layout space which has attributes which are a function of the layout space in which objects to be laid out in the layout space have a mutual relationship with each other comprising: a rule store means for storing a set of rules each of which has a condition section for applying the rule and a procedure section for determining a possible layout of an object in the layout space, different rules determining positions for laying out objects each having a shape; data structure generating means for generating data structures representing a current layout planning state to be used for determining layout positions of objects to be subsequently located in the layout space; rule calling and executing means for calling an appropriate rule from the rule store means and executing the rule depending upon an output from the data structure generating means with the result of execution of the rule being written in the data structure; and display means for displaying the data structure.