PURPOSE: To enable the inference and extraction of the design for which the difference of a seating location, etc., is taken into consideration by a little data base.
CONSTITUTION: In this design device provided with an evaluation term input means 3 inputting the evaluation term expressing a design image, an inference means 7 inferring a suitable design element by using a design data base M storing the relation of the evaluation term and a design element and the design data base M by the inputted evaluation term and an output means 5 outputting a design as an inference result, the device has classification means 7 and 17 classifying the design elements into a common design element affecting on plural attributes and a noncommon design element affecting on only a specified attribute and the inference means 7 performs an inference by taking plural affecting attributes into consideration in the case of the common design element and performs the inference by taking the affecting specified attribute into consideration in the case of the non-common design element.