Abstract: A current-balance switching regulator in which a plurality of switching power source portions are connected in parallel for the purpose of supplying a stabilized output voltage to a load. Each of the switching power source portions includes a switching control portion for controlling a switching element connected to the primary side of a transformer in accordance with the output voltage on the secondary side of the transformer. Current is detected on the primary side of the portions. When a current unbalance is detected, current balance is arranged by adding the amount of unbalance equally among the portions, so concentration of the load to a particular portion can be prevented. As a result of such averaging, the life of each portion can be lengthened. The portions are connected so that one is made a master and the rest are slaves, so the output voltage can be determined by a variable resistor or the like.