PURPOSE: To provide a wider range of radiation image by one imaging when performing radiograph test on the member wherein the thickness of a welding part changes inclining in the direction of welding line.

CONSTITUTION: This radiation absorbing plate 3 is used when performing radiograph test on the member wherein the thickness of a steel plate 1 and a welding part 2 change in inclination manner in the direction of welding line (ta-tb), and compensates radiation absorbing amount. Its configuration is so made that radiation absorbing amount changes in inclination manner in the direction of welding line, as radiation absorbing amount gets smaller at thinner portion (ta) of the steel plate 1 and that gets larger at thicker portion (tb).