PROBLEM TO BE SOLVED: To provide a measuring device using light, which is capable of measuring a wide area of a subject and easily adjustable to any shape that may be different from each subject.SOLUTION: This light measuring device comprises: transmitting optical fibers for irradiating the head of a subject with light and receiving optical fibers for receiving the light delivered to the subjects head, which are formed in a grid-like pattern, made up of a plurality of squares with sides of a regular length, so that the transmitting optical fibers and the receiving optical fibers are equally distanced from each other. The device also includes holders for holding the transmitting optical fibers and the receiving optical fibers at the crossing of the side ends of the squares. Since the holders 22 are capable of turning the direction of each side 23 in structure, the squares can be deformed as desired.COPYRIGHT: (C)2010,JPO&INPIT【課題】光による計測装置で、被検体の広い領域を計測し、かつ、被検体毎に形状の差異がある場合においても容易に対応可能な光計測装置を提供する。【解決手段】被検体頭部に光を照射する送光ファイバと、前記被検体頭部に照射された光を受光する受光ファイバと、当該送光ファイバと受光ファイバとの間の距離が一定となるように、辺の長さが一定である複数の四角形から構成され、当該四角形の辺の端部に前記送光ファイバまたは前記受光ファイバを保持する保持部を有する生体光計測装置において、前記保持部22により各辺23が回転可能な構造をもっており、前記四角形を変形させることが可能である。【選択図】図1