To provide a high-frequency branching/distributing circuit which has a small strain component generated in an up signal band even by connecting to a multi-channel high output amplifier like a bidirectional CATV amplifier and to provide a method for demagnetizing a high-frequency apparatus having the branching/distributing circuit.

When the high-frequency branching/distributing circuit having a transformer obtained by winding a lead on a ferrite is connected to the multi-channel high output amplifier like the bidirectional CATV amplifier, magnetization of the ferrite becomes a cause for generating the strain. In order to demagnetize the ferrite by stabilizing the magnetizing of the ferrite, the ferrite is demagnetized by using a demagnetizer after a soldering work of a component of the branching/distributing circuit and a mounting work of a printed circuit board are completed.