An electromagnetic wave sensor includes: a first wire which extends in a first direction; a second wire which extends in a second direction different from the first direction; and an electromagnetic wave detector which is electrically connected to the first wire and is electrically connected to the second wire, wherein the second wire is provided so as to leave an interval with respect to the first wire in a third direction orthogonal to the first direction and the second direction, and the second wire is disposed to three-dimensionally intersect the first wire. At least one wire of the first wire and the second wire includes a wide portion, which is wider than an average value of a width of a portion excluding an overlapping portion of the at least one wire, in the overlapping portion in which the first wire and the second wire overlap each other.