In this work, the effects of He ion and electron beam irradiations to the substrate-type CdTe solar cells, which was suitable for the detection of alpha and beta radiation, were investigated. He ion irradiation revealed that the induced current proportionally increased with the increase of He ion current and that it was possible to detect alpha radiation using the substrate-type CdTe solar cell dosimeter. Next, the electron irradiation effects were investigated. The induced current proportional to the electron flux was also observed, and the sensitivity depended on the electron energy. In addition, the degradation of substrate-type CdTe solar cell dosimeter by electron beam irradiation was investigated. No significant degradation in short-circuit current was observed by the electron irradiation of 3×1016 cm-2 at 200 keV and 1×1016 cm-2 at 400 keV. This result suggests that the substrate-type CdTe solar cell dosimeter is sufficiently resistant to electron irradiation.