A load testing machine, comprising: a first resistance unit to a sixth resistance unit (21 - 26); a first cooling fan to a sixth cooling fan (31 - 36); insulators between the first to sixth resistance units (21 - 26) and the first to sixth cooling fans (31 - 36); and either connection cables or short-circuit bars, wherein each of the first to sixth resistance units (21 - 26) includes a plurality of steps of resistor groups each formed of a plurality of rod-shaped resistors parallel to a x-direction arranged at predetermined intervals in a y-direction vertical to the x-direction, the resistor groups being arranged in a z-direction vertical to the x-direction and the y-direction, the first to sixth cooling fans (31 - 36) face the first to sixth resistance units (21 - 26), respectively, in the z-direction, the first to third resistance units are arranged in the x-direction at intervals of not smaller than a first distance, the fourth to sixth resistance units are arranged in the x-direction at intervals of not smaller than the first distance, the first and fourth resistance units are arranged in the y-direction at an interval of not smaller than a second distance, the second and fifth resistance units are arranged in the y-direction at an interval of not smaller than the second distance, the third and sixth resistance units are arranged in the y-direction at an interval of not smaller than the second distance, characterized in that either the connection cables or the short-circuit bars are connection members used for serially and detachably connecting, at more than one part, resistor groups next to each other in the y-direction of two resistance units next to each other in the y-direction with the interval of not smaller than the second distance in between, and the insulators each have a size corresponding to a rated voltage of a target power supply of a power supply load test to be conducted using a resistance unit group, the resistance unit group having serially connected resistor groups of two resistance units next to each other in the y-direction with the interval of not smaller than the second distance in between. a first resistance unit to a sixth resistance unit (21 - 26); a first cooling fan to a sixth cooling fan (31 - 36); insulators between the first to sixth resistance units (21 - 26) and the first to sixth cooling fans (31 - 36); and either connection cables or short-circuit bars, wherein each of the first to sixth resistance units (21 - 26) includes a plurality of steps of resistor groups each formed of a plurality of rod-shaped resistors parallel to a x-direction arranged at predetermined intervals in a y-direction vertical to the x-direction, the resistor groups being arranged in a z-direction vertical to the x-direction and the y-direction, the first to sixth cooling fans (31 - 36) face the first to sixth resistance units (21 - 26), respectively, in the z-direction, the first to third resistance units are arranged in the x-direction at intervals of not smaller than a first distance, the fourth to sixth resistance units are arranged in the x-direction at intervals of not smaller than the first distance, the first and fourth resistance units are arranged in the y-direction at an interval of not smaller than a second distance, the second and fifth resistance units are arranged in the y-direction at an interval of not smaller than the second distance, the third and sixth resistance units are arranged in the y-direction at an interval of not smaller than the second distance, characterized in that either the connection cables or the short-circuit bars are connection members used for serially and detachably connecting, at more than one part, resistor groups next to each other in the y-direction of two resistance units next to each other in the y-direction with the interval of not smaller than the second distance in between, and the insulators each have a size corresponding to a rated voltage of a target power supply of a power supply load test to be conducted using a resistance unit group, the resistance unit group having serially connected resistor groups of two resistance units next to each other in the y-direction with the interval of not smaller than the second distance in between.