There has recently been a significant increase in the number of diabetic patients. Self-monitoring of the glucose levels in a patient's blood is essential for treating diabetes. Generally, blood glucose measurement requires an invasive blood sampling. Therefore, patients are always plagued by issues such as pain, stress, and risk of blood-borne infection. The objective of this study is to develop a non-invasive blood glucose measurement device based on NIR spectroscopy. We compared the prediction accuracy of the individual calibration curve and summarized calibration curve, and took the analysis wavelength range into consideration as fundamental experiments for taking a non-invasive blood glucose measurement. As a result, a clinically effective level of accuracy and a high correlation were confirmed in the individual calibration curve, and an analysis using a smaller wavelength range has a good influence on the accuracy.