PROBLEM TO BE SOLVED: To provide a magnetic field generator for nuclear magnetic resonance having a wider bore space. A magnetic field generator for nuclear magnetic resonance according to the present invention includes a plurality of oxide superconducting bulk bodies having a ring-like structure having a structure in which a RE2BaCuO5 phase is dispersed in a single crystal REBa2Cu3Oy phase. A magnet unit and a storage tank that stores the magnet unit therein are provided, and the magnet unit includes a stacked body in which each of the plurality of oxide superconducting bulk bodies is coaxially and coaxially stacked, and the storage tank is Of the oxide superconducting bulk body of the outermost layer of the laminate, which is formed by a cylindrical storage tank inner wall provided along the inner peripheral surface of the magnet unit and a storage tank outer wall provided along the outer surface of the magnet unit. The inner diameter of at least one of the first oxide superconducting bulk bodies is smaller than the inner diameter of the second oxide superconducting bulk bodies other than the outermost layer of the laminated body, and the second oxide superconducting body on the inner wall of the storage tank. Smaller than the outer diameter of the portion located on the inner peripheral surface side of the electrically bulk. [Selection diagram] Figure 2【課題】本発明は、より広いボア空間を有する核磁気共鳴用磁場発生装置を提供する。【解決手段】本発明に係る核磁気共鳴用磁場発生装置は、単結晶状のＲＥＢａ２Ｃｕ３Ｏｙ相にＲＥ２ＢａＣｕＯ５相が分散した組織を有し、かつ、リング状である、複数の酸化物超電導バルク体を含む磁石ユニットと、磁石ユニットを内部に収容する収容槽と、を備え、磁石ユニットは、複数の酸化物超電導バルク体のそれぞれが、同軸かつ同軸方向に積層された積層体を含み、収容槽は、磁石ユニットの内周面に沿って設けられる筒状の収容槽内壁と、磁石ユニットの外表面に沿って設けられる収容槽外壁とで形成され、積層体の最外層の酸化物超電導バルク体のうちの少なくとも一方の第１酸化物超電導バルク体の内径は、積層体の最外層以外の第２酸化物超電導バルク体の内径よりも小さく、かつ、収容槽内壁における第２酸化物超電導バルク体の内周面側に位置する部分の外径よりも小さい。【選択図】図２
