A solder supply device provided with solder cup 70 housing liquid solder that is cylindrical and open at one end, and supply nozzle 74 that is inserted into the solder cup, that supplies solder from inside the solder cup by moving the solder cup by supplying air to space 86, wherein a fixed amount of air is supplied in a case in which the solder cup movement distance is less than a specified distance, and a greater amount of air than the above specified amount is supplied in a case in which the solder cup movement distance is the set movement distance or greater. That is, when supplying solder, in a case in which the volume of the space to which air is supplied is a specified volume or greater, a greater amount of air is supplied than the air supply amount for when the volume of the space is a specified volume or less. Thus, even in a case in which the volume of the space is equal to or greater than the specified volume, it is possible to supply the same amount of solder as the solder supply volume in a case in which the volume of the space is less than the specified volume, thus it is possible to control operation of the solder supply device considering differential head.