An electronic device is provided. The electronic device includes a first housing including a first conductive portion, a second housing slidably coupled to the first housing at a designated round-trip distance and configured to include a second conductive portion overlapping at least a part of the first conductive portion in a slide-in state, a wireless communication circuit disposed in the electronic device and electrically connected to the first conductive portion, and at least one electrical connection structure disposed in a second space of the second housing and configured to electrically connect the second conductive portion to the first conductive portion in the slide-in state. The wireless communication circuit may be configured to transmit and/or receive a radio signal in at least one frequency band through the first conductive portion and the second conductive portion in the slide-in state.