PROBLEM TO BE SOLVED: To provide a nail shape acquisition device, a drawing device, and a control program of a nail shape acquisition device capable of properly determining whether or not, a curved shape of a nail is acquired correctly, thereby, when it is estimated that, the curved shape of the nail is not acquired correctly, promoting so as to measure the curved shape of the nail again, and promoting so as to correct the acquired curved shape of the nail.SOLUTION: A nail shape acquisition device comprises: a shape acquisition part for acquiring a curved shape of a nail 11 based on an image which is acquired by imaging the nail 11； an index value acquisition part for acquiring an index value indicating a degree of curvature of the curved shape of the nail 11； and a determination part for, calculating a differential value of index values of nails 11 of a same kind of fingers 12 on left and right hands, and determining whether or not the differential value is equal to or higher than a threshold. When the differential value is higher than the threshold, it is estimated that the curved shape of the nail is not correctly acquired.SELECTED DRAWING: Figure 1【課題】爪の湾曲形状の取得が正しく行えているか否かを適切に判別することができ、それにより、爪の湾曲形状の取得が正しく行えていないと推定される場合に、再計測の実行を促したり、取得した湾曲形状の補正を促したりすることができる爪形状取得装置及び描画装置、並びに爪形状取得装置の制御プログラムを提供する。【解決手段】爪形状取得置は、爪１１を撮影して取得された画像に基づいて爪１１の湾曲形状を取得する形状取得部と、取得した爪１１の湾曲形状の湾曲の程度を表す指標値を取得する指標値取得部と、左右の手の同種の指１２の爪１１の指標値の差分値を算出し、差分値が閾値以上であるか否かを判定する判定部と、を備え、差分値が閾値より大きい場合に、湾曲形状の取得が正しく行えていないと推定する。【選択図】図１
