PROBLEM TO BE SOLVED: To provide a probe for a pulse oximeter in which a light emitting part and a light receiving part can be directly or substantially directly opposed to each other regardless of the thickness of a measurement object such as a fingertip. SOLUTION: A pair of housings (10, 20) are openably and closably supported, and an urging member (30) for urging the respective tip portions (10a, 20a) to approach each other is provided. Includes a base portion (33) and a pair of elastic arm portions (31, 32) extending from both ends of the base portion, and one first arm portion (31) is the first accommodation space of the first housing. The other second arm portion (32) is inserted into the second housing space (25) of the second housing so that the relative position of the first housing to the first arm portion can be changed. The displacement permitting section (12, 13, 22, 23, 52) is provided. [Selection diagram] Figure 2【課題】指先等の測定対象の太さにかかわらず発光部と受光部を正対又は略正対させることができるパルスオキシメータ用プローブを提供する。【解決手段】一対のハウジング（１０、２０）を開閉自在に支持し、それぞれの先端部（１０ａ、２０ａ）を互いに接近させるように付勢する付勢部材（３０）を備え、この付勢部材は、基部（３３）と、基部の両端からそれぞれ延び、弾性を有する一対の腕部（３１、３２）とを備え、一方の第１腕部（３１）は、第１ハウジングの第１収容空間（１５）内に挿通され、他方の第２腕部（３２）は、第２ハウジングの第２収容空間（２５）内に挿通され、第１腕部に対する第１ハウジングの相対位置を変更可能とする変位許容部（１２、１３、２２、２３、５２）を備える。【選択図】図２
