To provide a measuring device which can make accurate quantitative or qualitative analysis of the properties of organism tissue by making more district the signals related to the concentration change and physical property change of the component and the tissue.

A measuring device for the properties of a organism tissue, which measures organism tissue properties in a organism 3 non-invasively, is composed of a beam splitter 2 to divide into two beams the near infrared rays 1 which are coherent or similar to it, a reflection mirror 4 to reflect one of the split beams 1a of the infrared rays so that it 1a interferes with the other beams 1b which has been reflected by the vital organism structure, a sensor 5 to sense the signal according to the reflective beam 1c having undergone an interference, and an information processing means 7 to make computational processing of the signal sensed by the sensor 5. It is arranged so that the position of the reflection mirror 4 relative to the reflective beam 1d reflected by the organism tissue can be set any as desired.