PURPOSE: To remove smoothly etchant which stays on the surface of a printed board non-uniformly and avoid non-uniform etching over the whole surface of the board by a method wherein the spraying times of the etchant sprayed from respective header pipes are changed successively and periodically.

CONSTITUTION: A swinging lever 25 swings around a shaft by the driving of an oscillation motor as shown by arrows and oscillation arms 24 are moved to left and right directions. Then links 31 attached to the oscillation arms 24 are made to swing to the left and right around the axes of header pipes 1a-1f. Thus the spraying range of etchant sprayed from etching nozzles 3 is changed with the lapse of time. With this constitution, the header pipes 1a-1f from which the etchant is practically not sprayed are produced successively and the etchant on a printed board is smoothly moved to the side of the header from which the etchant is not sprayed and the uniform etching conditions can be obtained.