An electromagnetic wave detection apparatus 10 includes a separator 16, a first detector 17, a switching unit 18, and a second detector 20. The separator 16 is capable of switching between a separation state and a non-separation state. The separator 16 separates incident electromagnetic waves to travel in a first direction d1 and a second direction d2, in the separation state. The first detector 17 detects electromagnetic waves traveling in the first direction d1. The switching unit 18 includes a plurality of switching elements “se”. Each switching element “se” is capable of switching a traveling direction of electromagnetic waves traveling in the second direction d2 between a third direction d3 and a fourth direction d4. The second detector 20 detects electromagnetic waves traveling in the third direction d3.