To provide a solder composition which can form a solder layer with uniform thickness under good control at an electrode part of an electronic component or circuit board, and can form the solder layer without solder bridging even when an electrode interval is small, and a solder supply method using it.

The solder composition has an oxide film on its surface and is composed of 30 to 95 wt.% solder powder containing 0.02 to 0.2 wt.% oxygen, an acid component which dissolves oxides, and a base agent containing its solvent. After the solder composition 2 is applied to or mounted on an electrode array area of a circuit board, the solder composition 2 is heated to fuse solder powder 3 and solder balls 4 of specific size when deposited in multiple layers as solder powder is united together are cooled to form a solder layer 5 on an electrode.