A power supply device that includes a plurality of capacitors including a plurality of lead terminals; a circuit board including a conductive path; a relay terminal configured to connect the lead terminals to the conductive path of the circuit board; and a cover configured to cover the plurality of lead terminals of the plurality of capacitors, wherein the plurality of capacitors are oriented such that the respective lead terminals are disposed on an inner side, and the relay terminal includes a plurality of pressure contacts configured to come into pressure contact with a plurality of lead terminals of the plurality of capacitors, the lead terminals having the same potential, and a board connector configured to be connected to the conductive path of the circuit board, a number of the board connector being smaller than a number of the plurality of pressure contacts.