PURPOSE: To automatically coat a material to be coated by controlling a spray gun provided to a reciprocator and a gear for traveling the material which is made movable in the direction orthogonal to the spray gun by an air sequence.

CONSTITUTION: In an automatic coater for coating a comparatively large surface, a spray gun 54 operated by compressed air, a reciprocator 24 to reciprocate the spray gun 54 which is operated by compressed air and a gear 62 for traveling a material to be coated in the direction orthogonal to the traveling direction of the spray gun 54 which is operated by compressed air are provided. The automatic coater is composed of a console section 10, a reciprocating section 12, a spray gun section 14 and a vertically moving section 16. The spray gun 54 of the reciprocator 24 and the traveling gear 62 are controlled in accordance with an air sequence. The material is automatically coated in this way.