PURPOSE: To facilitate the widthwise adjustment, etc., when applying 1 or ≥2 liquid agent layers to a moving web body or coating the body with these layers by providing the inserts with at least one metering ports defined by two wall surfaces and freely attachably and detachably mounting insertion ports of a prescribed length and width to the metering parts.

CONSTITUTION: This coating hopper has adjacent, hopper elements 4 mounted to respectively form the metering ports 11 with each other. The ends of the hopper are closed by end plates 8 via end gaskets 7 made of rubber. The slot inserts 5 cut to the exact length and width are mounted to the ends of the respective metering ports 11 from the apex of the hopper. The slot inserts 5 are formed from material, such as plastic, metal or paper, and precisely control the coating width of the coating solution when the slot inserts are mounted in the metering ports 11. The slot inserts are made easily and rapidly removable from the metering ports 11 at the time of ending of the coating to products. The washing of the inside and outside of the hopper is executed in the removed state of the insert 5.