To provide a photoelectric smoke sensor with excellent responsiveness while allowing smoke to smoothly enter from the outside.

The photoelectric smoke sensor 1 includes: a labyrinth structure 17 which blocks external light while allowing smoke to enter from the outside and forms a smoke detection space; a light emitter 13 which emits light to the smoke detection space 19 formed by the labyrinth structure 17; and a light receiver 15 which receives light from the light emitter 13, which is scattered by smoke particles in the smoke detection space 19. The labyrinth structure 17 is rotatably installed.