An ionizing radiation conversion device of the present disclosure includes a first electrode, a second electrode, and an ionizing radiation conversion layer disposed between the first electrode and the second electrode. Here, the first electrode contains a first metal, the second electrode contains at least one selected from the group consisting of second metals and metal oxides, and the ionizing radiation conversion layer contains a perovskite compound. The difference of a value of electron affinity of the ionizing radiation conversion layer minus a value of work function of the first electrode is greater than or equal to 0 eV and less than or equal to 0.4 eV.