Fecha de publicación: 02/06/2004 Fuente: Wipo "Sensorization" The present invention relates to a structure of a diffraction-grating type sensor chip (surface plasmon resonance sensor chip) for analyzing a sample using surface plasmon resonance (SPR), and also relates to a method of and an apparatus for analyzing a sample using the sensor chip. A surface plasmon resonance sensor chip (1) according to the present invention comprises: a metal layer (3) along whose surface a surface plasmon wave can be induced by light irradiation; and a plurality of diffraction grating surfaces (5a-5i) which are disposed in the vicinity of said metal layer (3) and on each of which a diffraction grating with a uniform groove orientation and a uniform groove pitch is formed so as to generate an evanescent wave upon light irradiation; wherein the groove pitch and the groove orientation of each said diffraction grating surface (5a-5i, 251-254), in addition to the angle that each said diffraction grating surface (5a-5i, 251-254) forms with a predetermined reference plane (S0), are adjusted in such a manner that when said diffraction grating surfaces (5a-5i, 251-254) are projected onto a predetermined projection plane, the groove orientations in the projection plane are identical while the groove pitches in the projection plane are different among said diffraction grating surfaces (5a-5i, 251-254). With this arrangement, even when irradiating with light in parallel, the intensity of the light reflected from the diffraction grating surface (5a-5i, 251-254) has a certain distribution. It is therefore possible to calculate a resonance angle for the whole sensor surface in real-time, based on both the intensity of the reflection light from the diffraction grating surface (5a-5i) and the substantial incident angle to the diffraction grating surface (5a-5i, 251-254). Besides, when carrying out analysis based on the variation between the reflection-light intensity, it is possible to substantially enlarge a measurement range.