PROBLEM TO BE SOLVED: To provide a device capable of accurately calculating a light transmittance of blood.SOLUTION: A component measurement device includes: a light-emitting element 12 arranged to irradiate a measurement light 16 onto a first area 2b and a second area 2c a light receiving element for measurement 22a arranged to detect a reflected light 17 reflected by the first area 2b and to output a first light intensity Os a light receiving element for reference 22b arranged to detect the reflected light 17 in the second area 2c and to output a second light intensity Or a memory arranged to store a light passing rate α that is a rate of the measurement light 16 passing through a measurement target part 55 in the first area 2b and the second area 2c and a light absorption spectrum calculator arranged to calculate a light transmittance Ti of the measurement target part 55 using the light passing rate α, the first light intensity Os and the second light intensity Or.SELECTED DRAWING: Figure 7COPYRIGHT: (C)2016,JPO&INPIT【課題】精度良く血液の光透過率を演算する装置を提供する。【解決手段】成分測定装置は第1領域2b及び第2領域2cに測定光16を照射する発光素子12と、第1領域2bにて反射した反射光17を検出し第1光強度Osを出力する測定用受光素子22aと、第2領域2cにて反射光17を検出し第2光強度Orを出力する参照用受光素子22bと、第1領域2b及び第2領域2cにおいて測定部位55を測定光16が通過する割合である光通過割合αを記憶するメモリーと、光通過割合αと第1光強度Osと第2光強度Orとを用いて測定部位55の透過率Tiを演算する吸光スペクトル算出部と、を備える。【選択図】図7
