A nuclear medicine diagnosis apparatus for obtaining data for nuclear medicine of a subject based on radioactive rays generated from the subject having radiopharmaceuticals administered thereto, comprising: a first measuring device adapted to measure a first variation with time that is a variation with time of the data for nuclear medicine received from a γ-ray detector as pixel information of a pixel and obtained by a variety of radiopharmaceuticals of mutually different nuclides having been administered at a same administration point in time; a deriving device adapted to obtain a second variation with time, for each radiopharmaceutical J, that is a function aJ(αJ, βJ, γJ,...,, t) indicating an accumulated amount varying with time of the radiopharmaceutical in the subject, wherein αJ, βJ, γJ,..., are N of unknown numbers, based on the first variation with time; wherein the first measuring device is adapted to measure the first variation with time at at least MxN points in time, when a number of radiopharmaceuticals administered is M, such that the deriving device is able to determine, for every radiopharmaceutical M, the N of unknown numbers giving the function aJ(αJ, βJ, γJ,..., t) indicating the accumulated amount in the pixel; an acquiring device adapted to acquire the accumulated image of each radiopharmaceutical based on the second variation with time; and a storing device that has stored beforehand the function aJ(αJ, βJ, γJ,..., t) indicating the accumulated amount of each radiopharmaceutical, wherein the apparatus is adapted to specify the radiopharmaceutical in the accumulated image based on the function of the accumulated amount of each radiopharmaceutical that has been stored beforehand. a first measuring device adapted to measure a first variation with time that is a variation with time of the data for nuclear medicine received from a γ-ray detector as pixel information of a pixel and obtained by a variety of radiopharmaceuticals of mutually different nuclides having been administered at a same administration point in time; a deriving device adapted to obtain a second variation with time, for each radiopharmaceutical J, that is a function aJ(αJ, βJ, γJ,...,, t) indicating an accumulated amount varying with time of the radiopharmaceutical in the subject, wherein αJ, βJ, γJ,..., are N of unknown numbers, based on the first variation with time; wherein the first measuring device is adapted to measure the first variation with time at at least MxN points in time, when a number of radiopharmaceuticals administered is M, such that the deriving device is able to determine, for every radiopharmaceutical M, the N of unknown numbers giving the function aJ(αJ, βJ, γJ,..., t) indicating the accumulated amount in the pixel; an acquiring device adapted to acquire the accumulated image of each radiopharmaceutical based on the second variation with time; and a storing device that has stored beforehand the function aJ(αJ, βJ, γJ,..., t) indicating the accumulated amount of each radiopharmaceutical, wherein the apparatus is adapted to specify the radiopharmaceutical in the accumulated image based on the function of the accumulated amount of each radiopharmaceutical that has been stored beforehand.