PURPOSE: To determine each block of an integrated circuit in scale, arrangement, and shape so as to set up the layout of the integrated to meet a necessary performance.

CONSTITUTION: An initial floor plan determining section 11 which determines the blocks of an integrated circuit in circuit scale and arrangement and executes a floor planning operation, a floor planning evaluation section 12 which determines the blocks of the integrated circuit in shape, computes the area of all the integrated circuit and an estimate of the length of an inter-block wiring based on the positions of the blocks and the data of inter-block connection, and furthermore evaluates a floor planning operation based on a calculated evaluation function, and a floor planning repetition improving section 13 which modifies a floor plan, evaluates the modified floor plan, and judges that a floor plan is replaced or repeated judging that the modified floor plan is adopted or not are provided.