An image forming apparatus capable of shortening a time needed for the assembly work is provided. The image forming apparatus of the invention comprises a low-voltage power supply and a housing, wherein the low-voltage power supply includes a substrate provided with a low-voltage power supply circuit, a pair of connection cords each connected to the substrate and an external power supply, a casing made of metal and provided with an accommodation portion inside which the substrate is fixed and a notch located on an opening edge of the accommodation portion, a lid body made of metal and configured to cover the accommodation portion and to define a cord insertion port by closing the notch, and a ring body made of resin and inserted into the notch in a state where both the connection cords are inserted in the ring body and to be attached to the cord insertion port.