Problem:The problem is to provide a fluorescent material for a scintillator to be used in a radiation detector. In view of this, the fluorescent material must have a high fluorescent intensity and a low level of afterglow 1 to 300 ms after the termination of X-ray radiation.Solution:The above problem is solved in that the above fluorescent material contains Ce as an activator. In addition, the material contain at least Gd, Al, Ga, O, Si, and a component M. The component M is at least one of Mg, Ti, and Ni. In addition, the composition of the material must be expressed by the general formula: (Gd1−x−zLuxCez)3+a(Al1−u−sGauScs)5−aO12 wherein 0≦a≦0.15, 0≦x≦0.5, 0.0003≦z≦0.0167, 0.2≦u≦0.6, and 0≦s≦0.1, and wherein, regarding the concentrations of Si and M, 0.5≦Si concentration (mass ppm)≦10, and 0≦M concentration (mass ppm)≦50.