A gamma-ray image acquisition device using Compton scattering, comprising: a gas chamber; a scattered gamma-ray detector for detecting a target scattered gamma-ray generated by Compton scattering of an incident gamma-ray that enters said chamber from an external space, and acquiring a detected position and energy of said target scattered gamma-ray; a scattering position acquisition part for acquiring a scattering position of said incident gamma-ray in said chamber; a scattering direction acquisition part for acquiring a direction of said target scattered gamma-ray on the basis of said scattering position and said detected position; a two-dimensional gas amplification position detector and a recoil electron information acquisition part for acquiring a direction and energy of a recoil electron recoiling from said scattering position; an incident gamma-ray calculator for acquiring an incident direction and energy of the corresponding incident gamma-ray from the direction and energy of said target scattered gamma-ray and the direction and energy of said recoil electron; and an image acquisition part for acquiring a two-dimensional image by imaging spectroscopy based on incident directions and energies of a plurality of incident gamma-rays, the two-dimensional image being an image in which each pixel corresponding to the incident direction of incident gamma-rays includes energy distribution information, characterized in that in said two-dimensional image, an area and a solid angle of an imaging range are proportional to each other, a point spread function is obtainable from measurements or simulations using an angular resolution measure and a scatter plane deviation, wherein: the angular resolution measure is defined as a width of a circular ring-shaped region in a plane perpendicular to a direction of the target scattered gamma-ray, the scatter plane deviation is defined by a vector indicating the scattering direction of the target scattered gamma-ray and a vector indicating the recoil direction of the recoil electron, and the scatter plane deviation is used to narrow down the circular ring-shaped region in the angular direction, and a full width at half maximum of the point spread function that indicates accuracy of said incident direction acquired by said incident gamma-ray calculator corresponds to a visual angle less than or equal to 15 degrees. a gas chamber; a scattered gamma-ray detector for detecting a target scattered gamma-ray generated by Compton scattering of an incident gamma-ray that enters said chamber from an external space, and acquiring a detected position and energy of said target scattered gamma-ray; a scattering position acquisition part for acquiring a scattering position of said incident gamma-ray in said chamber; a scattering direction acquisition part for acquiring a direction of said target scattered gamma-ray on the basis of said scattering position and said detected position; a two-dimensional gas amplification position detector and a recoil electron information acquisition part for acquiring a direction and energy of a recoil electron recoiling from said scattering position; an incident gamma-ray calculator for acquiring an incident direction and energy of the corresponding incident gamma-ray from the direction and energy of said target scattered gamma-ray and the direction and energy of said recoil electron; and an image acquisition part for acquiring a two-dimensional image by imaging spectroscopy based on incident directions and energies of a plurality of incident gamma-rays, the two-dimensional image being an image in which each pixel corresponding to the incident direction of incident gamma-rays includes energy distribution information, characterized in that in said two-dimensional image, an area and a solid angle of an imaging range are proportional to each other, a point spread function is obtainable from measurements or simulations using an angular resolution measure and a scatter plane deviation, wherein: the angular resolution measure is defined as a width of a circular ring-shaped region in a plane perpendicular to a direction of the target scattered gamma-ray, the scatter plane deviation is defined by a vector indicating the scattering direction of the target scattered gamma-ray and a vector indicating the recoil direction of the recoil electron, and the scatter plane deviation is used to narrow down the circular ring-shaped region in the angular direction, and the angular resolution measure is defined as a width of a circular ring-shaped region in a plane perpendicular to a direction of the target scattered gamma-ray, the scatter plane deviation is defined by a vector indicating the scattering direction of the target scattered gamma-ray and a vector indicating the recoil direction of the recoil electron, and the scatter plane deviation is used to narrow down the circular ring-shaped region in the angular direction, and a full width at half maximum of the point spread function that indicates accuracy of said incident direction acquired by said incident gamma-ray calculator corresponds to a visual angle less than or equal to 15 degrees.