There is provided a radiographic apparatus (1) that does not have any restrictions on its position when performing imaging, distinguishes natural radiation from X-rays emitted from an X-ray generator in real time, detects a start of X-ray emission, and can prevent wrong detection of a start of X-ray emission due to natural radiation. When a signal value that is output from a radiation sensor (25) moves out of a predetermined range, an irradiation start detecting unit (22) of the radiographic apparatus (1) does not determine whether the signal value output from the radiation sensor (25) is a signal value outside the predetermined range until a predetermined masking time (”tm) has passed since the signal value moved out of the predetermined range. When the number of times the signal value output from the radiation sensor (25) moves out of the predetermined range within a predetermined time (”T) since the signal value output from the radiation sensor (25) first moved out of the predetermined range reaches a predetermined number (N), the irradiation start detecting unit (22) detects a start of X-ray emission from the X-ray generator.
