In a X-ray imaging apparatus an estimation unit estimates a cumulative exposure dose of X-rays irradiated onto an object, and a remaining exposure tolerance dose calculation unit calculates a remaining exposure tolerance dose using a difference between a tolerated maximum exposure dose and the cumulative exposure dose. A X-ray irradiation tolerance period calculation unit calculates an X-ray irradiation tolerance period using a difference between a predetermined scheduled X-ray irradiation period and an actual irradiation period of X-rays irradiated onto the object, an X-ray irradiation reference dose calculation unit calculates reference dose per unit time that will form a basis for irradiation based on the remaining exposure tolerance dose and the X-ray irradiation tolerance period, and a control unit that controls X-ray irradiation of the object by setting dose per unit time within the X-ray irradiation tolerance period based on the reference dose.