A device for X-ray analysis of a sample (1), including: a generation system for the generation of an X-ray beam to irradiate an analysis zone of the sample, said analysis zone defining a analysis mean plane, and the X-ray beam being emitted along a direction of incidence; a detection system for the detection, in at least one dimension, of X-rays diffracted by the irradiated analysis zone. An analyser system located between the sample and the detection system and includes an X-ray diffracting surface forming a partial surface of revolution about an axis of revolution being contained in the analysis mean plane, with the axis of revolution being distinct from the direction of incidence and passing through the centre of the analysis zone, and with the diffracting surface being oriented so as to diffract the X-rays toward the detection system.