PROBLEM TO BE SOLVED: To provide a measuring apparatus having further reduced size, a measuring method, and a parameter setting method.SOLUTION: This measuring apparatus is provided with: a light receiving element, which is provided at a position facing a region to be measured, the region having disposed therein a subject to be measured, and which makes light form an image, the light having been transmitted from the region to be measured； a plurality of light emitting elements, which are disposed at the periphery of the light receiving element, and output light for measuring the subject to be measured； and a reflective optical element, which is provided above the light emitting elements, and guides, to the region to be measured, the light emitted from the light emitting elements. The light receiving surface of the light receiving element, and the light output surfaces of the light emitting elements are positioned on a same plane, the light emitted from the light emitting elements is reflected by the reflective optical element, and the center lines of the light emitted from respective light emitting elements pass through substantially the center of the region to be measured.【課題】装置の更なる小型化を図ることが可能な、測定装置、測定方法及びパラメータの設定方法を提供すること。【解決手段】本開示に係る測定装置は、測定対象物の載置された測定対象領域と対向する位置に設けられ、当該測定対象領域からの光が結像する受光素子と、前記受光素子の周囲に配設され、前記測定対象物を測定するための光を射出する複数の発光素子と、前記発光素子の上方に設けられ、当該発光素子から射出された放射発光を、前記測定対象領域へと導光する反射光学素子と、を備え、前記受光素子の受光面と、前記複数の発光素子の光射出面とは、互いに同一の平面上に位置しており、前記複数の発光素子から射出された前記放射発光は前記反射光学素子により反射され、それぞれの前記発光素子からの前記放射発光の中心線が前記測定対象領域の略中心を通過する。【選択図】図２Ｂ
