An X-ray diffractometer (1, 31) for obtaining X-ray diffraction angles of diffracted X-rays by detecting with an X-ray detector (5, 35) diffracted X-rays diffracted at a sample, when X-rays are irradiated onto the sample, at angles (2 θ, 2 θχ) about a center point of a goniometer circle (GC1, GC2), the X-ray diffractometer (1, 31) comprising: an X-ray source configured to emit X-rays which are irradiated onto the sample; the X-ray detector (5, 35) configured to rotatably move along the goniometer circle (GC1, GC2) about the center point of the goniometer circle (GC1, GC2) and to detect X-rays diffracted at the sample; and an X-ray shield member (4, 24a, 24b, 34) provided with an X-ray passage port (15, 25, 45), characterized in that: the X-ray shield member (4, 24a, 24b, 34) is disposed in a position where the X-ray passage port (15, 25, 45) includes the center point of the goniometer circle (GC1, GC2); and wherein the X-ray shield member (4, 24a, 24b, 34) is configured so that: X-rays diffracted at the sample so as to pass through the center point of the goniometer circle (GC1, GC2) pass through the X-ray passage port (15, 25, 45); and X-rays diffracted at the sample so as to pass through areas other than the center point of the goniometer circle (GC1, GC2) are shielded by the X-ray shield member (4, 24a, 24b, 34), wherein the expression "pass through the center point of the goniometer circle" includes the case in which diffracted X-rays pass through the center point itself and the case in which the X-rays pass near the center point, wherein the term "near" is set in accordance with a degree of definition being sought in a diffraction image. the X-ray diffractometer (1, 31) comprising: an X-ray source configured to emit X-rays which are irradiated onto the sample; the X-ray detector (5, 35) configured to rotatably move along the goniometer circle (GC1, GC2) about the center point of the goniometer circle (GC1, GC2) and to detect X-rays diffracted at the sample; and an X-ray shield member (4, 24a, 24b, 34) provided with an X-ray passage port (15, 25, 45), an X-ray source configured to emit X-rays which are irradiated onto the sample; the X-ray detector (5, 35) configured to rotatably move along the goniometer circle (GC1, GC2) about the center point of the goniometer circle (GC1, GC2) and to detect X-rays diffracted at the sample; and an X-ray shield member (4, 24a, 24b, 34) provided with an X-ray passage port (15, 25, 45), characterized in that: the X-ray shield member (4, 24a, 24b, 34) is disposed in a position where the X-ray passage port (15, 25, 45) includes the center point of the goniometer circle (GC1, GC2); and wherein the X-ray shield member (4, 24a, 24b, 34) is configured so that: X-rays diffracted at the sample so as to pass through the center point of the goniometer circle (GC1, GC2) pass through the X-ray passage port (15, 25, 45); and X-rays diffracted at the sample so as to pass through areas other than the center point of the goniometer circle (GC1, GC2) are shielded by the X-ray shield member (4, 24a, 24b, 34), wherein the expression "pass through the center point of the goniometer circle" includes the case in which diffracted X-rays pass through the center point itself and the case in which the X-rays pass near the center point, wherein the term "near" is set in accordance with a degree of definition being sought in a diffraction image. the X-ray shield member (4, 24a, 24b, 34) is disposed in a position where the X-ray passage port (15, 25, 45) includes the center point of the goniometer circle (GC1, GC2); and wherein the X-ray shield member (4, 24a, 24b, 34) is configured so that: X-rays diffracted at the sample so as to pass through the center point of the goniometer circle (GC1, GC2) pass through the X-ray passage port (15, 25, 45); and X-rays diffracted at the sample so as to pass through areas other than the center point of the goniometer circle (GC1, GC2) are shielded by the X-ray shield member (4, 24a, 24b, 34), X-rays diffracted at the sample so as to pass through the center point of the goniometer circle (GC1, GC2) pass through the X-ray passage port (15, 25, 45); and X-rays diffracted at the sample so as to pass through areas other than the center point of the goniometer circle (GC1, GC2) are shielded by the X-ray shield member (4, 24a, 24b, 34), wherein the expression "pass through the center point of the goniometer circle" includes the case in which diffracted X-rays pass through the center point itself and the case in which the X-rays pass near the center point, wherein the term "near" is set in accordance with a degree of definition being sought in a diffraction image.