PURPOSE: To simplify the processing in the case of insertion of a logic circuit.

CONSTITUTION: This logic circuit generating system is provided with a logic circuit read means 1 which reads in a logic circuit file 7, a macro circuit inserting means 2 which inserts another logic circuit (macro circuit) to the read-in logic circuit, a connection information designating means 3 which designates connection information of the original circuit and the inserted macro circuit, a connection destination deleting means 4 which deletes the circuit made unnecessary by macro insertion from the original circuit, a macro circuit connecting means 5 which connects the macro circuit to the original circuit based on connection information, and a logic circuit means 6 which writes a generated logic circuit in the file.