PURPOSE: To sustain operation of sound loads by disconnecting only an abnormal load from power supply section upon occurrence of abnormality therein.

CONSTITUTION: Upon occurrence of abnormality in any one of electronic machines Z1, Z2...Zn. input current to abnormal machine (Z1, Z2...Zn) exhibits an increment of δIi. The incremental input current δli is fed to a power supply output monitoring circuit 15 and an abnormality detecting circuit 16 in order to detect an abnormal machine(Z1, Z2...Zn). A power supply output stop/load disconnecting control section 17 for thus detected abnormal machine (Z1, Z2...Zn) performs voltage supply interrupting control of load disconnecting circuits 13a, 13b...13n for supplying voltage to abnormal machine (Z1, Z2...Zn).