A design support apparatus includes a storage that stores first layout data and pattern data, the first layout data indicating a circuit pattern of a design target circuit, the circuit pattern including circuit patterns, dummy patterns of the component circuits, and a wiring pattern, the component circuits being included in the design target circuit, the pattern data indicating a second dummy pattern, the second dummy pattern having a shape different from a shape of a first dummy pattern, the first dummy pattern being included in the first layout data, and a processor coupled to the storage, configured to specifies a component circuit, the specified component circuit being included in an area in the arrangement area, extracts pattern data indicating a dummy pattern, generates second layout data, the second layout data indicating a circuit pattern, and outputs the second layout data.