A scintillator, which has a first surface and a second surface that are not located on a same surface, the scintillator comprising: multiple first phases (11, 13, 14) extending in an extending direction, wherein the extending direction is a direction from the first surface to the second surface; and a second phase (12, 13, 14) positioned around the multiple first phases (11, 13, 14) to fill sides of the first phases, wherein: the multiple first phases have a first refractive index with respect to a wavelength range of scintillator light of the scintillator; the second phase has a second refractive index with respect to the wavelength range of the scintillator light of the scintillator; the first refractive index is different from the second refractive index such that either the multiple first phases or the second phase constitutes a lower refractive index phase and the other of the multiple first phases and the second phase constitutes a higher refractive index phase; the refractive index of the lower refractive index phase with respect to the wavelength range of the scintillator light of the scintillator is lower than the refractive index of the higher refractive index phase with respect to the wavelength range of the scintillator light of the scintillator; and at least the higher refractive index phase generates the scintillator light if being exposed to irradiation with radiation; characterized in that the scintillator further comprises an absorbing portion for absorbing the scintillator light, the absorbing portion being provided between the first surface and the second surface such that it extends the lower refractive index phase in the extending direction, and an absorption coefficient of the absorbing portion for the scintillator light is finite. multiple first phases (11, 13, 14) extending in an extending direction, wherein the extending direction is a direction from the first surface to the second surface; and a second phase (12, 13, 14) positioned around the multiple first phases (11, 13, 14) to fill sides of the first phases, wherein: the multiple first phases have a first refractive index with respect to a wavelength range of scintillator light of the scintillator; the second phase has a second refractive index with respect to the wavelength range of the scintillator light of the scintillator; the first refractive index is different from the second refractive index such that either the multiple first phases or the second phase constitutes a lower refractive index phase and the other of the multiple first phases and the second phase constitutes a higher refractive index phase; the refractive index of the lower refractive index phase with respect to the wavelength range of the scintillator light of the scintillator is lower than the refractive index of the higher refractive index phase with respect to the wavelength range of the scintillator light of the scintillator; and at least the higher refractive index phase generates the scintillator light if being exposed to irradiation with radiation; the multiple first phases have a first refractive index with respect to a wavelength range of scintillator light of the scintillator; the second phase has a second refractive index with respect to the wavelength range of the scintillator light of the scintillator; the first refractive index is different from the second refractive index such that either the multiple first phases or the second phase constitutes a lower refractive index phase and the other of the multiple first phases and the second phase constitutes a higher refractive index phase; the refractive index of the lower refractive index phase with respect to the wavelength range of the scintillator light of the scintillator is lower than the refractive index of the higher refractive index phase with respect to the wavelength range of the scintillator light of the scintillator; and at least the higher refractive index phase generates the scintillator light if being exposed to irradiation with radiation; characterized in that the scintillator further comprises an absorbing portion for absorbing the scintillator light, the absorbing portion being provided between the first surface and the second surface such that it extends the lower refractive index phase in the extending direction, and an absorption coefficient of the absorbing portion for the scintillator light is finite.