An electronic device, comprising: a housing including a first housing, a second housing and a hinge housing; a flexible display disposed over the first housing, the second housing and the hinge housing; a hinge assembly assembled to the hinge housing, the hinge assembly being configured to rotate the first housing about a first rotation axis and to rotate the second housing about a second rotation axis; a first hinge plate covering at least part of the hinge assembly and coupled to the first housing, the first hinge plate configured to support a first region of the flexible display; a second hinge plate covering at least part of the hinge assembly and coupled to the second housing, the second hinge plate configured to support a second region of the flexible display; wherein the hinge assembly includes a support portion disposed between the hinge housing and the flexible display, and extending in parallel to the first rotation axis and the second rotation axis, wherein the support portion comprises: a center portion disposed between the first hinge plate and the second hinge plate and configured to support a third region of the flexible display between the first region and the second region when the housing is in an 180-degree unfolded state; a first support portion formed at a first side with respect to the center portion and configured to support a part of the first hinge plate when the housing is in the 180-degree unfolded state and being configured to be separated from the part of the first hinge plate when the housing is not in the 180-degree unfolded state; and a second support portion formed at a second side with respect to the center portion and configured to support a part of the second hinge plate when the housing is in the 180-degree unfolded state, and being configured to be separated from the part of the second hinge plate when the housing is not in the 180-degree unfolded state, wherein when top-viewed in a direction substantially perpendicular to the support portion in the 180-degree unfolded state, the part of the first hinge plate and the part of the second hinge plate is overlapped a portion of the support portion. a housing including a first housing, a second housing and a hinge housing; a flexible display disposed over the first housing, the second housing and the hinge housing; a hinge assembly assembled to the hinge housing, the hinge assembly being configured to rotate the first housing about a first rotation axis and to rotate the second housing about a second rotation axis; a first hinge plate covering at least part of the hinge assembly and coupled to the first housing, the first hinge plate configured to support a first region of the flexible display; a second hinge plate covering at least part of the hinge assembly and coupled to the second housing, the second hinge plate configured to support a second region of the flexible display; wherein the hinge assembly includes a support portion disposed between the hinge housing and the flexible display, and extending in parallel to the first rotation axis and the second rotation axis, wherein the support portion comprises: a center portion disposed between the first hinge plate and the second hinge plate and configured to support a third region of the flexible display between the first region and the second region when the housing is in an 180-degree unfolded state; a first support portion formed at a first side with respect to the center portion and configured to support a part of the first hinge plate when the housing is in the 180-degree unfolded state and being configured to be separated from the part of the first hinge plate when the housing is not in the 180-degree unfolded state; and a second support portion formed at a second side with respect to the center portion and configured to support a part of the second hinge plate when the housing is in the 180-degree unfolded state, and being configured to be separated from the part of the second hinge plate when the housing is not in the 180-degree unfolded state, wherein when top-viewed in a direction substantially perpendicular to the support portion in the 180-degree unfolded state, the part of the first hinge plate and the part of the second hinge plate is overlapped a portion of the support portion. a center portion disposed between the first hinge plate and the second hinge plate and configured to support a third region of the flexible display between the first region and the second region when the housing is in an 180-degree unfolded state; a first support portion formed at a first side with respect to the center portion and configured to support a part of the first hinge plate when the housing is in the 180-degree unfolded state and being configured to be separated from the part of the first hinge plate when the housing is not in the 180-degree unfolded state; and a second support portion formed at a second side with respect to the center portion and configured to support a part of the second hinge plate when the housing is in the 180-degree unfolded state, and being configured to be separated from the part of the second hinge plate when the housing is not in the 180-degree unfolded state, wherein when top-viewed in a direction substantially perpendicular to the support portion in the 180-degree unfolded state, the part of the first hinge plate and the part of the second hinge plate is overlapped a portion of the support portion.