An electromagnetic wave detection apparatus causes electromagnetic waves incident on a reference surface to propagate in a particular direction using each of the pixels, a detector to detect electromagnetic waves incident on a detection surface, and a second propagation unit that includes a first surface opposing the reference surface, a second surface opposing the detection surface, and a third surface intersecting the first and second surface. The third surface causes electromagnetic waves propagating in a first direction to propagate in a second direction. The first surface causes electromagnetic waves propagating in a second direction to be incident on the reference surface and causes electromagnetic waves re-incident from the reference surface to propagate in a third direction. The third surface causes electromagnetic waves propagating in the third direction to propagate in a fourth direction. The second surface emits electromagnetic waves propagating in the fourth direction to the detection surface.