An electronic device comprising: a foldable housing comprising: a first housing ; a second housing connected to one side of the first housing and being rotatable through a first hinge module and disposed to at least partially face the first housing in a folded state; and a third housing connected to an opposite side of the first housing and being rotatable through a second hinge module and disposed to at least partially face the first housing in a folded state, wherein, in a folded state, the foldable housing further comprises: a pen accommodating part defined through a spaced space between a first edge of the second housing and a second edge of the third housing ; a flexible display extending from at least a portion of the second housing to at least a portion of the third housing through the first housing ; and an electronic pen at least partially accommodated in the pen accommodating part and comprising at least one magnetic force reaction member inside the electronic pen , wherein the electronic device further comprises at least one magnetic force generating member disposed around the first edge of the second housing and/or the second edge of the third housing , and wherein, when the electronic pen is mounted in the pen accommodating part , the location of the electronic pen is maintained through the magnetic force reaction member . a foldable housing comprising: a first housing ; a second housing connected to one side of the first housing and being rotatable through a first hinge module and disposed to at least partially face the first housing in a folded state; and a third housing connected to an opposite side of the first housing and being rotatable through a second hinge module and disposed to at least partially face the first housing in a folded state, wherein, in a folded state, the foldable housing further comprises: a pen accommodating part defined through a spaced space between a first edge of the second housing and a second edge of the third housing ; a first housing ; a second housing connected to one side of the first housing and being rotatable through a first hinge module and disposed to at least partially face the first housing in a folded state; and a third housing connected to an opposite side of the first housing and being rotatable through a second hinge module and disposed to at least partially face the first housing in a folded state, wherein, in a folded state, the foldable housing further comprises: a pen accommodating part defined through a spaced space between a first edge of the second housing and a second edge of the third housing ; a flexible display extending from at least a portion of the second housing to at least a portion of the third housing through the first housing ; and an electronic pen at least partially accommodated in the pen accommodating part and comprising at least one magnetic force reaction member inside the electronic pen , wherein the electronic device further comprises at least one magnetic force generating member disposed around the first edge of the second housing and/or the second edge of the third housing , and wherein, when the electronic pen is mounted in the pen accommodating part , the location of the electronic pen is maintained through the magnetic force reaction member . <EOS>