PROBLEM TO BE SOLVED: To provide a sensor, measuring apparatus, and measuring system capable of stably acquiring biological information of a subject.SOLUTION: The sensor includes a light-emitting part for exiting measuring light, a light-receiving part 230 for detecting scattering light according to the measuring light, and a package 210 on which the light-emitting part and the light-receiving part are mounted. The package includes a first recess 214 and a second recess 216, the light-emitting part is mounted on a first bottom surface 214c of the first recess, and the light-receiving part is mounted on a second bottom surface 216c of the second recess. A slope angle of a first lateral face 214a of the first recess, in a side close to the second recess, with respect to the first bottom surface is smaller than the slope angle of a second lateral face 214b of the first recess, in a side distant from the second recess, with respect to the first bottom surface.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2018,JPO&INPIT【課題】被検者の生体情報を安定して取得できるセンサ、測定装置及び測定システムを提供する。【解決手段】測定光を射出する発光部と、測定光に応じた散乱光を検出する受光部230と、発光部と受光部とが実装されるパッケージ210とを備え、パッケージは、第1凹部214と、第2凹部216とを有し、発光部は、第1凹部の第1底面214cに実装され、受光部は、第2凹部の第2底面216cに実装され、第1凹部の、第2凹部に近い側の第1側面214aの、第1底面に対する傾斜角は、第1凹部の、第2凹部から遠い側の第2側面214bの、第1底面に対する傾斜角よりも小さい。【選択図】図4