A glass antenna arranged on a vehicle window glass includes a slot antenna formed by cutting out a conductive film; and a power supply unit configured to supply power to the slot antenna. The slot antenna includes a first slot extending in a first direction; a second slot connected to one end of the first slot, and extending in a second direction, a first wide-width slot connected to the other end of the first slot directly or via a first connection slot, and having a slot width greater than that of the first slot, and a second wide-width slot connected to a terminal end portion of the second slot directly or via a second connection slot, and having a slot width greater than that of the second slot. The power supply unit is arranged so as to straddle the first slot.