A musical keyboard instrument which not only allows a music stand to be erected in a desired position in the transverse direction on a panel section, but also ensures easiness of viewing a written musical score of a music book even when the music stand is erected in the vicinity of the left or right end of the panel section. A keyboard section includes a plurality of keys arranged in a front part thereof. A panel section is provided at a location rearward of the keyboard section. An arcuate groove part is formed in the panel section, for engagement with leg parts of a music stand. The arcuate groove part is formed such that the leg parts of the music stand can be engaged therewith in a desired position in the transverse direction, and is curved in a rearwardly convex manner.