A defogger is disposed in or on a rear window glass sheet. The rear window glass sheet has an H-oriented antenna conductor for frequency band H higher than frequency band L, an L-oriented antenna conductor for frequency band L, and a feeding point disposed in a blank space thereof above the defogger therein or thereon, the feeding point being connected to the H-oriented antenna conductor and the L-oriented antenna conductor, the H-oriented antenna conductor comprising H-oriented antenna elements, the L-oriented antenna conductor comprising L-oriented antenna elements and a directivity-adjusting antenna element, the directivity-adjusting antenna element being connected to the L-oriented antenna elements, a first H-oriented antenna element and a first L-oriented antenna element being capacitively coupled, and a second H-oriented antenna element and a second L-oriented antenna element being capacitively coupled.