To provide a manufacturing method of a bearing free from contact between solid bodies by filling an lubricating oil between a shaft (sleeve) and a sleeve mating shaft, increasing the pressure of the lubricating oil by rotation of the shaft, and supporting the shaft by the pressure by floating from the sleeve mating shaft.

The shaft (sleeve) and the sleeve mating shaft are manufactured by an electrocast product, there is a hole in the center of the shaft (sleeve), and the lubricating oil sealed in this hole tends to go outside by centrifugal force. When there is a through-hole in this sleeve, the lubricating oil oozes out to a clearance between the sleeve and the sleeve mating shaft in response to a rotating speed.