A radio wave radiating device includes: a radio wave supply unit extending in one direction, one end of the radio wave supply unit being connected to a power source, an earth part spaced apart from the radio wave supply unit by a predetermined distance in a direction intersecting with the one direction, extending in the one direction, one end of the earth part being connected to a ground, and a radiating element connected to another end of the radio wave supply unit and another end of the earth part, respectively, and configured to radiate a radio wave received from the radio wave supply unit. The radiating element includes a middle portion connecting the radio wave supply unit and the earth part, a first radiating portion extending in a direction away from the earth part, and a second radiating portion extending in a direction away from the radio wave supply unit.