To restore design data at a desired point of time without depending on manual layout design operation.
The device comprises an editing part which forms and updates design data of a circuit including circuit parts and lines for mutually connecting the circuit parts; a design database which stores the design data of the circuit; a history database which stores, upon update of the design data, an update history record showing the update content in association with a circuit part updated or a line updated in the design data; an extraction reference receiving part which receives an extraction reference for extracting a specific update history record from the update history stored in the history database; a history extraction part which extracts the update history record from the history database according to the extraction reference; and a restoration part which forms design data of the circuit before update shown by the extracted update history record from the design data of the circuit.
Akira Hirakawa
Daisuke Takada
Tsutomu Toyama