A CPU of an overdubbing device plays back a music file recorded in a memory card of the device and outputs the file as a played-back audio signal while mixing the played-back audio signal with an external audio signal input from the outside, to thus perform overdubbing. A music file recorded through overdubbing last time is automatically set as a playback music file for the next time, and a selected state of means for selecting execution/nonexecution of overdubbing is maintained as the state of execution. As a result, overdubbing is enabled by twice operations of a record key, whereby the operation is made identical with operation performed during ordinary recording.