1. A cassette storing therein a radiation conversion panel for detecting a radiation emitted from a radiation source that has passed through a patient, and converting the detected radiation into radiation image information, the cassette comprising: a detecting unit for detecting a movement of the patient from a given image capturing posture with respect to the cassette during a process of acquiring the radiation image information by emitting the radiation from the radiation source to the patient; and an image capture inhibiting unit for inhibiting the radiation image information of the patient from being captured, wherein the detecting unit is provided inside the cassette and configured to detect a load applied to the cassette by the patient, the radiation source is configured to continue emitting the radiation toward the patient when the detecting unit detects no load or an amount of movement of the patient is equal to or smaller than an allowable range in relation to an irradiation time of the radiation, and the image capture inhibiting unit is configured to inhibit the radiation image information of the patient from being captured when the detecting unit detects the amount of movement of the patient greater than an allowable range in relation to the irradiation time of the radiation.