PURPOSE: To uniformly cure coating material ink on the surface of a work by mounting a long-sized UV curing light source in the main body of an irradiator and providing a control body for averaging the UV intensity in the width direction of the work between the light source and the work.

CONSTITUTION: A long-sized UV curing light source 2 is provided in a box- shaped irradiator main body 1, and a control body 3 is furnished between the light source 2 and a work. The control body 3 is set so that UV transmission is decreased in the vicinity of the center of the light source 2 and increased toward both ends. As a result, the UV intensity is averaged in the width direction of the work of glass, metal, paper, etc., to be conveyed by a conveyor, etc., and the coating material or ink on the work surface is uniformly cured. A glass body with the surface frosted, an expandable glass and a wire mesh are used for the control body 3.