An electronic device is provided. The electronic device includes a housing including a first plate, a second plate directed in an opposite direction to the first plate, and a side member surrounding a space between the first plate and the second plate and being combined with or being integrally formed with the second plate, a display configured to be seen through at least a part of the first plate, an antenna structure arranged inside the housing, the antenna structure including a first conductive layer including a first region including a first U-shaped slot and a second region coming in contact with the first region, and a second conductive layer facing the first conductive layer to be spaced apart from the first conductive layer, and including a third region including a second U-shaped slot facing the first U-shaped slot and a fourth region coming in contact with the third region and facing the second region, and at least one wireless communication circuitry electrically connected to the first conductive layer or the second conductive layer and configured to transmit and/or receive a signal having a frequency in a range of 3 GHz to 100 GHz. Other various embodiments are possible.