PURPOSE: To make it possible to continuously manufacture oxide superconducting wires of stable quality by enabling repeated application of a liquid containing a compound for the formation of an oxide superconductor to be dealt with the same device, and enabling the thickness of the liquid applied to be controlled to a uniform, and excellently thin state.

CONSTITUTION: An application thickness controller has a plurality of rolls 1, a pinch mechanism 2 for the rolls, a drive source for rotating the rolls in the direction in which the advance of a supporting cable 4 is inverted, and a mechanism 3 for removing a liquid 5 attached to each roll, the liquid 5 containing a compound for the formation of an oxide superconductor.