To provide an X-ray detection element that can exclude scattered X rays efficiently with a simple structure, has high sensitivity, and integrates a collimator, and to provide an X-ray detector using the X-ray detection element.

In the X-ray detection element, an X-ray detection semiconductor having a number of X-ray detection elements arranged one-dimensionally, and an X-ray obstruction member are overlapped alternately for lamination. The X-ray detector utilizing the X-ray detection element comprises the X-ray detection element; a bias application section for applying a bias voltage to the X-ray detection element; and a reading section for reading a signal from the X-ray detection element via wiring.