Disclosed is a hair growth-stimulating device (10, 11, 12, 13, 14) using light, said hair growth-stimulating device comprising an irradiation unit (20) for irradiating the skin with near infrared light and a blood flow amount-measuring unit (90, 100) for measuring the amount of blood flowing within the skin that is irradiated with the near infrared light. According to this hair growth-stimulating device using light, the irradiation with near infrared light is carried out simultaneously with the measurement of the blood flow amount by taking advantage of the phenomenon that the irradiation with near infrared light causes an increase in the blood flow amount within the thus irradiated skin. Thus, it can be understood whether or not the irradiation site is appropriately irradiated with near infrared light. As a result, the irradiation site can be efficiently irradiated with near infrared light and, in its turn, hair growth can be stimulated.本發明的照光生髮器(10、11、12、13、14)，具備：對皮膚照射近紅外光的照射器(20)，及測量照射近紅外光的皮膚內部之血流量的血流量測量裝置(90、100)。根據此照光生髮器，利用進行近紅外線照射之皮膚內部的血流量增加的特性，與近紅外線照射同時進行血流量測量，可檢測出近紅外光對於照射部位的適當照射。其結果，有效進行對照射部位之近紅外線照射，可促進生髮。
