A load testing machines includes: six resistance units; six cooling fans; insulators between the resistance units and the cooling fans; and connection cables, in which: each of the resistance units includes a plurality of steps of resistor groups arranged in a z-direction and each formed of a plurality of rod-shaped resistors parallel to a x-direction connected together in series arranged at predetermined intervals in a y-direction; the six cooling fans face the resistance units, respectively, in the z-direction; the connection cables are cables used for serially and detachably connecting resistor groups next to each other in the y-direction of two resistance units next to each other in the y-direction with an interval of not smaller than a second distance in between; and the insulators each have a size corresponding to the rated voltage of a target power supply of a power supply load test to be conducted using a resistance unit group.