1. An X-ray analysis apparatus comprising: a radiation source configured to irradiate a radiant ray to a sample; a radiant ray adjustment mechanism configured to adjust an intensity of the radiant ray; an X-ray detector configured to detect a characteristic X-ray and a scattered X-ray, which are radiated from the sample, and output a signal including energy information of the characteristic X-ray and the scattered X-ray; an analyzer configured to analyze the signal; an incident X-ray adjustment mechanism disposed between the sample and the X-ray detector, and configured to adjust a total intensity of the characteristic X-ray and the scattered X-ray, which are entered to the X-ray detector; and a control section configured to control the incident X-ray adjustment mechanism and the radiant ray adjustment mechanism such that the total intensity of the characteristic X-ray and the scattered X-ray, which are detected by the X-ray detector, is approximately a maximum obtainable X-ray intensity, and an intensity of the radiant ray becomes within a normal operation range of a radiant ray irradiation power of the radiation source.