A sensor head is provided and achieves improved measurement accuracy while reducing measurement time. The sensor head includes: a case including a first case section having a lens therein, a second case section having an objective lens therein, and a third case section providing connection between the first case section and the second case section. Inside the third case section, a mirror member for folding light incident thereon from the lens toward the objective lens is disposed, and a hollow tube providing communication between through holes respectively formed in the mirror member and the objective lens is provided.