PURPOSE: To avoid cross-talk and improve energy resolution by providing a shielding grid on a radiation incident surface.
CONSTITUTION: A semiconductor substrate 6 is made of Si, GaAs, CdTe, HgI or the like and charge clouds (a) of electron-hole pairs are created in the substrate 6 by an incident radiation. On the radiation incident surface of the semiconductor substrate 6, charge collecting electrodes 8 which collect the charge clouds (a) and a shielding grid 9 between the collecting electrodes 8 are provided. The shielding grid 9 is made of material (such as lead Pb or tungsten W) which has high radiation blocking capability and is composed of a shielding layer 9a and an insulating layer 96 which insulates the shielding layer 9a from the charge collecting electrodes 8. A common electrode 7 is provided so as to face the charge collecting electrodes 8 with the semiconductor substrate 6 between.