The present invention pertains to an optical measurement device and method, whereby component values of an object can be more precisely measured. This optical measurement device: emits irradiation light including a prescribed irradiation wavelength band, said irradiation light being irradiated on to an object receives the irradiation light on a side surface thereof and scatters same internally and receives surface-reflected light and internally-reflected light by using a plurality of pixels and measures the received light volumes, said surface reflected light being irradiation light reflected by the surface of the object substantially without wavelength shift, said internally-reflected light being irradiated light that has shifted a prescribed excitation wavelength band from the irradiation wavelength band inside the object and has been reflected, and said irradiated light being irradiated on to the surface of the object via a light-guide plate that substantially uniformly irradiates from an irradiation surface having a wider area than a side surface, on to a prescribed range on the object surface. The present invention can be applied, for example, to optical measurement devices, electronic devices, body composition measurement instruments, imaging devices, and information processing devices, etc.La présente invention se rapporte à un dispositif et un procédé de mesure optique, les valeurs des composantes dun objet pouvant être mesurées avec plus de précision. Le dispositif de mesure optique de linvention : émet une lumière dirradiation comprenant une bande de longueur donde dirradiation prescrite, ladite lumière dirradiation étant envoyée sur un objet reçoit la lumière envoyée sur une surface latérale de lobjet et diffuse ladite lumière vers lintérieur et reçoit la lumière réfléchie par la surface et la lumière réfléchie de manière interne à laide dune pluralité de pixels, et mesure les volumes lumineux reçus, ladite lumière réfléchie par la surface étant la lumi
