TRANSFORMER

A transformer, according to one embodiment, includes a core unit, a first coil unit and a second coil unit, and a terminal bobbin coupled to one side of the second coil unit in a first direction, wherein the first coil unit includes a first coil and a first bobbin, wherein the second coil unit includes a second coil and a second bobbin, wherein the terminal bobbin includes a plurality of first terminals disposed on one side of the terminal bobbin that is oriented in the first direction, and an opening formed in another side opposite the one side in the first direction to allow one side of the second coil unit to be inserted thereinto, and wherein two end portions of the first coil are led out from the first bobbin and are respectively connected to different first terminals among the plurality of first terminals of the terminal bobbin.