A three-dimensional miniaturized power supply is composed of at least two of a first circuit board and a second circuit board which are assembled in a chamber of a container in a three-dimensional spatial form, wherein an insulation spacing, which is in compliance with an ITE safety regulation, is provided between a circuit of the first circuit board and a circuit of the second circuit board, allowing an area and a volume of the power supply to be miniaturized, such that the power supply can be emplaced in a small container.