1. A radiographic apparatus having radiation emitting means for emitting radiation toward an object under examination, radiation detecting means for detecting radiation transmitted through the object under examination, and signal sampling means for taking radiation detection signals from the radiation detecting means at predetermined sampling time intervals, for obtaining radiographic images based on the radiation detection signals outputted from the radiation detecting means at the predetermined sampling time intervals as radiation is emitted to the object under examination, said apparatus comprising: time lag removing means for removing lag-behind parts from the radiation detection signals by a recursive computation, on an assumption that a lag-behind part included in each of said radiation detection signals taken at the predetermined sampling time intervals is due to an impulse response formed of a single exponential function or a plurality of exponential functions with different attenuation time constants; response coefficient to dose relationship storage means for storing, in advance, a relationship of correspondence between impulse response coefficients, which determine conditions relating to the impulse response in the recursive computation performed by said time lag removing means, and radiation doses; and impulse response coefficient setting means for setting an impulse response coefficient corresponding to a radiation dose for the object under examination based on the relationship of correspondence between impulse response coefficients and radiation doses stored in the response coefficient to dose relationship storage means; wherein said time lag removing means is arranged to obtain corrected radiation detection signals by performing the recursive computation based on the impulse response coefficient set by the impulse response coefficient setting means, to remove the lag-behind parts from the radiation detection signals.