PURPOSE: To attain excellent picture, by irradiating radiant ray transmitted through an object onto a storable fluorescent sheet laminate so as to store and record two radiant ray pictures different from picture information and obtaining a subtraction picture from each radiant ray picture.

CONSTITUTION: The storable fluorescent sheet laminates where plural storable fluorescent sheets are laminated, the storable fluorescent sheet filter laminates where plural storable fluorescent sheets are laminated together with a filter comprising a low energy component absorbing substance, or the storable fluorescent sheet 5 having a specific constitution is used as an X-ray detector. The radiant ray transmitting the object 7 including a specific structure where the radiant energy absorbing characteristics is different from that of others is irradiated on the laminate or sheet 5, at least ≥2 radiant ray pictures having different picture information corresponding to the specific structure are stored and recorded, each radiant ray picture is read out so as to obtain the subtraction picture.