A power supply device, for connection to an inductive load, comprising: a plurality of secondary batteries ; a current shutdown switch connected to an output side of the secondary batteries , the current shutdown switch being formed of a semiconductor element; a control circuit that controls turn-on and turn-off of the current shutdown switch ; characterized in that the power supply device further comprises :- a spike absorption circuit arranged between a positive terminal and a negative terminal of the output side of the power supply device, said terminals arranged for output from the secondary batteries , and the current shutdown switch , the spike absorption circuit including a series circuit of a protection switch and a diode , the protection switch being formed of a semiconductor element; a small-signal switch that controls turn-on and turn-off of the protection switch ; and a delay circuit that maintains the small-signal switch in an ON state over a predetermined setup time (T) after a current shutdown timing has come, the current shutdown timing being a timing when the current shutdown switch is switched to an OFF state, wherein the diode is connected, in a reverse direction, between the positive terminal and the negative terminal, and the delay circuit maintains the small-signal switch in the ON state over the setup time (T) after the current shutdown timing of the current shutdown switch , the small-signal switch in the ON state causes the protection switch to be switched to an ON state, and the spike absorption circuit damps a kickback voltage, said kickback voltage arising when the current shutdown switch is switched to the OFF state in the presence of an inductance at the load side of the power supply device. a plurality of secondary batteries ; a current shutdown switch connected to an output side of the secondary batteries , the current shutdown switch being formed of a semiconductor element; a control circuit that controls turn-on and turn-off of the current shutdown switch ; a spike absorption circuit arranged between a positive terminal and a negative terminal of the output side of the power supply device, said terminals arranged for output from the secondary batteries , and the current shutdown switch , the spike absorption circuit including a series circuit of a protection switch and a diode , the protection switch being formed of a semiconductor element; a small-signal switch that controls turn-on and turn-off of the protection switch ; and a delay circuit that maintains the small-signal switch in an ON state over a predetermined setup time (T) after a current shutdown timing has come, the current shutdown timing being a timing when the current shutdown switch is switched to an OFF state, wherein the diode is connected, in a reverse direction, between the positive terminal and the negative terminal, and the delay circuit maintains the small-signal switch in the ON state over the setup time (T) after the current shutdown timing of the current shutdown switch , the small-signal switch in the ON state causes the protection switch to be switched to an ON state, and the spike absorption circuit damps a kickback voltage, said kickback voltage arising when the current shutdown switch is switched to the OFF state in the presence of an inductance at the load side of the power supply device. <EOS>