According to an embodiment of the disclosure, there may be provided a foldable electronic device. A foldable electronic device may include a flexible
printed circuit board (FPCB). The foldable electronic device may comprise a first housing including a first component, a second housing including a second component, a hinge
assembly rotatably connecting the first housing and the second housing, a
flexible display disposed from the first housing across a folding area where the hinge
assembly is disposed to the second housing, and a flexible
printed circuit board electrically connecting the first component and the second component, including a plurality of
layers, and including a flexible portion corresponding to the folding area and rigid portions at one end and another end of the flexible portion. A
signal line for transmitting a
signal and / or power included in the plurality of
layers of the flexible
printed circuit board may include a
metal material and include a first area, a second area, and a third area classified according to a degree of bending in a folding area of the flexible printed circuit board. At least one layer among the plurality of
layers may be formed so that the
metal material has different thicknesses in the first area, the second area, and the third area on a same layer. Other various embodiments may also apply.