To definitely prevent a coating material from being attached to anything other than an objective surface to be coated of an object to be coated.

A rotation coater M in which a hollow shaft 3 is rotatably supported on a bearing housing 2 fixed to a base 1 through a bearing 4, an adsorption surface 8b of an optical base material 8 is fixed to an adsorption end 3b at an upper end of the shaft 3 by vacuum adsorption and is rotated to drop and apply a coating material 22 to the surface to be coated 8a is provided, wherein a coaxial fluid guide cylinder 2a is provided on the shaft 3, a fluid 12 is supplied into a clearance g between the shaft 3 and the cylinder 2a through a fluid pipe 11 and a fluid supply hole 2b from a fluid supply source 10, and the fluid is sprayed onto an outer edge 8c of the surface 8b in the material 8 from the upper end of the cylinder 2a, thereby definitely preventing droplets of the material 22 from being attached to the surface 8b by wraparound.