An apparatus, which is configured to generate random numbers as identification numerical values for uniquely identifying an identification target among a plurality of identification targets, the apparatus comprising an apparatus including a pulse generation device and a memory, the pulse generation device including: an emitter (1, 3), which includes a radioisotope containing a number of atoms greater than a total number of the plurality of identification targets; and a detector, which is configured to detect an α particle, a β ray, and/or a γ ray (hereinafter referred to as "α particle and others") emitted from the emitter due to spontaneous decay of an atomic nucleus to generate electric pulses, the memory being configured to store an initial pulse count of electric pulses obtained by measuring, at a time of initial measurement, for a given period of time, the electric pulses that are generated in the pulse generation device, a date of the initial measurement, and an initial identification numerical value obtained by digitizing a pulse interval between the electric pulses, wherein a plurality of first identification numerical values that are obtained through digitizing wave height values of the electric pulses generated by the pulse generation device, and a plurality of second identification numerical values that are obtained by digitizing the pulse interval between the electric pulses, are arranged into a matrix, and two identification numerical values in a combination of one of the first identification numerical values and one of the second identification numerical values are joined to each other, or added to each other, or multiplied by each other, or calculated by XOR operation after conversion into a binary number, to thereby generate the identification numerical values for uniquely identifying the identification target among the plurality of identification targets. the apparatus comprising an apparatus including a pulse generation device and a memory, the pulse generation device including: an emitter (1, 3), which includes a radioisotope containing a number of atoms greater than a total number of the plurality of identification targets; and a detector, which is configured to detect an α particle, a β ray, and/or a γ ray (hereinafter referred to as "α particle and others") emitted from the emitter due to spontaneous decay of an atomic nucleus to generate electric pulses, an emitter (1, 3), which includes a radioisotope containing a number of atoms greater than a total number of the plurality of identification targets; and a detector, which is configured to detect an α particle, a β ray, and/or a γ ray (hereinafter referred to as "α particle and others") emitted from the emitter due to spontaneous decay of an atomic nucleus to generate electric pulses, the memory being configured to store an initial pulse count of electric pulses obtained by measuring, at a time of initial measurement, for a given period of time, the electric pulses that are generated in the pulse generation device, a date of the initial measurement, and an initial identification numerical value obtained by digitizing a pulse interval between the electric pulses, wherein a plurality of first identification numerical values that are obtained through digitizing wave height values of the electric pulses generated by the pulse generation device, and a plurality of second identification numerical values that are obtained by digitizing the pulse interval between the electric pulses, are arranged into a matrix, and two identification numerical values in a combination of one of the first identification numerical values and one of the second identification numerical values are joined to each other, or added to each other, or multiplied by each other, or calculated by XOR operation after conversion into a binary number, to thereby generate the identification numerical values for uniquely identifying the identification target among the plurality of identification targets.