Magnetic equilibria of central regions of the plasma in a regime with the current hole with a large radius in JT-60U have been analysed. The analysis was based on solutions of the Grad–Shafranov equation with prescribed dependence of the poloidal flux function Ψ on minor radius at the outer midplane, corresponding to experimentally measured current density j|| profile. The code separates total toroidal current density into Ohmic plus externally driven (jex), bootstrap (jbs) and Pfirsch–Schlüter (jps) contributions. Under experimental conditions of JT-60U, the latter was found to dominate at the edge of the current hole. The experimentally observed sharp j|| rise at the edge of the current hole is mostly attributed to jps. This is caused by very high safety factor q at the edge of the current hole (∼100 or larger), which both increases Pfirsch–Schlüter current and decreases relative contribution of the bootstrap current (the latter—due to high dimensionless electron collisionality νe*, with the plasma being in the plateau collisionality regime). The results also reveal an important role played by Ohmic and/or externally driven current (e.g. by electron cyclotron current drive) at the edge of the current hole, for existence of closed magnetic surfaces. A certain amount of jex is necessary to compensate for negative Pfirsch–Schlüter current at the inboard side of the current hole edge, which may otherwise cause a local drop in poloidal magnetic field and the formation of an internal X-point.