An apparatus for beta-emission two-dimensional imaging including: a beta ray detector configured to receive, from an imaging target containing a first nuclide and a second nuclide, a beta ray based on the first or second nuclide and thereby detect the beta ray, the beta ray detector outputting a beta ray detection signal including location information indicating a detection location of the beta ray on a two-dimensional basis; a gamma ray detector configured to detect a gamma ray, the gamma ray detector detecting the first and second peculiar gamma rays in a discriminable manner; and an imaging processor configured to be capable of generating a distribution image of the first nuclide and a distribution image of the second nuclide in a discriminable manner.