An electrical circuit board on which an electronic control unit (10A, 10B) is formed, the electrical circuit board comprising: a first circuit pattern that forms an electrical circuit corresponding to a single first power supply voltage; a single power supply connection portion suitable to be connected with an upstream power supply line that supplies the single first power supply voltage, wherein the single power supply connection portion is connected to the first circuit pattern; a second circuit pattern that forms an electrical circuit corresponding to a plurality of second power supply voltages; an inter-board connection portion suitable to be connected with a second circuit board, the second circuit board being able to supply a power supply voltage from a second power supply line and a power supply voltage from the second power supply line converted by a DC/DC circuit unit; wherein the inter-board connection portion is connected to the first and the second circuit pattern; the electrical circuit board further comprising: a plurality of fuse holders (16A to 16C) independent from each other, wherein in each fuse holder (16A to 16C), a predetermined fuse is mounted, and each fuse holder (16A to 16C) has a first mounting position in which the fuse is connectable to the first circuit pattern and a second mounting position in which the fuse is connectable to the second circuit pattern; and a plurality of trunk line connection portions (22A to 22C) for connecting to a plurality of downstream power supply trunk lines, wherein each of the plurality of trunk line connection portions (22A to 22C) is connected to the fuse holders (16A to 16C). a first circuit pattern that forms an electrical circuit corresponding to a single first power supply voltage; a single power supply connection portion suitable to be connected with an upstream power supply line that supplies the single first power supply voltage, wherein the single power supply connection portion is connected to the first circuit pattern; a second circuit pattern that forms an electrical circuit corresponding to a plurality of second power supply voltages; an inter-board connection portion suitable to be connected with a second circuit board, the second circuit board being able to supply a power supply voltage from a second power supply line and a power supply voltage from the second power supply line converted by a DC/DC circuit unit; wherein the inter-board connection portion is connected to the first and the second circuit pattern; the electrical circuit board further comprising: a plurality of fuse holders (16A to 16C) independent from each other, wherein in each fuse holder (16A to 16C), a predetermined fuse is mounted, and each fuse holder (16A to 16C) has a first mounting position in which the fuse is connectable to the first circuit pattern and a second mounting position in which the fuse is connectable to the second circuit pattern; and a plurality of trunk line connection portions (22A to 22C) for connecting to a plurality of downstream power supply trunk lines, wherein each of the plurality of trunk line connection portions (22A to 22C) is connected to the fuse holders (16A to 16C). a plurality of fuse holders (16A to 16C) independent from each other, wherein in each fuse holder (16A to 16C), a predetermined fuse is mounted, and each fuse holder (16A to 16C) has a first mounting position in which the fuse is connectable to the first circuit pattern and a second mounting position in which the fuse is connectable to the second circuit pattern; and in each fuse holder (16A to 16C), a predetermined fuse is mounted, and each fuse holder (16A to 16C) has a first mounting position in which the fuse is connectable to the first circuit pattern and a second mounting position in which the fuse is connectable to the second circuit pattern; and a plurality of trunk line connection portions (22A to 22C) for connecting to a plurality of downstream power supply trunk lines, wherein each of the plurality of trunk line connection portions (22A to 22C) is connected to the fuse holders (16A to 16C).