An explosion-proof apparatus includes a pressure resistant explosion-proof case, heater, manifold, and analyzer unit. The heater is disposed in the pressure resistant explosion-proof case. The manifold is heated by the heater in the pressure resistant explosion-proof case and supplies heat from the heater to an outside of the pressure resistant explosion-proof case by heat conduction. The analyzer unit is disposed outside the pressure resistant explosion-proof case in contact with the manifold, and is heated by heat supplied from the manifold.