<p>It is possible to provide an AV composite editor and so forth capable of performing an editing operation for an audio signal and a video signal with high operability and in a small space. The AV composite editor comprises an effect category selecting means (E1) for selecting one of a plurality of effect categories and an effect mode selecting means (E4) for selecting a signal as a target of an effect processing. The AV composite editor changes the specification of an effect operation screen (210) according to the result of the selection of the effect category selecting means (E1), and does not change the specification of the effect operation screen (210) depending on the result of the selection of the effect mode selecting means (E4).</p>
