To provide a method for coating a lubricant capable of simplifying configuration of a device used in coating and of suppressing time required for drying in a path for supplying a plug to a piercing mill, and also to provide an equipment row of regenerating the plug used for the same.

In the method for coating the lubricant on the surface of the plug 1 circulatingly used in the piercing mill employed for manufacture of a seamless steel tube, the lubricant is coated on the surface to form a lubricating film without rotating the plug 1, and the plug is used in piercing rolling without drying the lubricating film. In the method for coating the lubricant, when the lubricant is coated on the surface of the plug 1, the lubricant is preferably coated over the half-circumference of the surface of the plug 1.