To provide an explosion-proof type luminaire, capable of providing plural types of light distributions with a single, simple structure

Cylinder-shaped socket holders 3 are disposed at both the ends of an explosion-proof type luminaire main body 1, and a straight-tube type lamp 11 mounted to a lamp protection cylinder 9 is disposed between the socket holders 3 on both ends. In addition, a ring is turnably provided to the cylinder- shaped socket holder 3 disposed at both the ends of the luminaire main body, a plurality of protrusions are provided on an outer periphery of the socket holder 3 at given intervals, a positioning support body is engaged in-between the protrusions of the socket holders 3 from the outside of the ring, so that the angle of a reflector 12 fixed to the top face of the ring can be variable by turning the ring.