A radiation imaging apparatus with high spatial resolution including semiconductor radiation detectors arranged on a wiring board capable of detecting γ-rays by separating their positions in the direction of incidence of γ-rays is provided. A semiconductor radiation detector is constructed by including five semiconductor devices made up of, for example, CdTe rectangular parallelepiped plates, a cathode electrode on one side of the semiconductor device, an anode electrode on the other side of the semiconductor device and an insulator for coating five semiconductor detection devices from the outside. The semiconductor radiation detector is mounted on a wiring board using an anode pin and a cathode pin.