To provide a radioactive image tube with high resolution and manufacture thereof.

This radioactive image tube is provided with an input part, having a radioactive exciting fluorescent layer 20 formed on the surface of a substrate 19, whereas the radioactive exciting fluorescent layer 20 involves a first fluorescent layer 20A consisting of columnar crystal formed on the surface of the substrate 19 with the thickness, equivalent to or less than 1/3 of that of the fluorescent layer 20, and a second fluorescent layer 20B consisting of columnar crystal formed on the first fluorescent layer 20A and the average diameter of the columnar crystal of the second fluorescent layer 20B is formed, so as to be larger than that of the columnar crystal of the second fluorescent layer 20A.