A radar apparatus is provided that is capable of providing desired directivity without preventing downsizing of the apparatus. In the radar apparatus, an antenna for at least either transmitting radar waves or receiving reflected waves is protected by a radome. Provided on an opposing face that is a face of the radome opposing the antenna is a wall section protruding from the opposing face of the radome into a space of the radome and extending along at least a portion of an outline of an aperture projection. The aperture projection is a projection of an aperture of the antenna onto the opposing face in a normal direction to the aperture.