The present invention relates to an educational string instrument comprising: a body provided with a head portion and a bottom portion; a nut installed on the head portion; a saddle installed on the bottom portion; a plurality of fixing parts installed on an outer side of the nut of the body; a plurality of tuning devices installed on an outer side of the saddle of the body; a plurality of strings supported by the fixing parts and the tuning devices and installed to be spaced apart from the body by the nut and the saddle, and a single fret installed to be inwardly spaced apart from an inner side of the nut to form a fingerboard part and functioning for raising an original note of the string by a semitone.