Abstract: The invention relates to an incinerator for crematories, including a combustion chamber provided with charge inlet, flue gas outlet, supply means for combustion air, heat supply means and ash outlet. The novelty resides in the fact that the combustion chamber is placed in a unit which is movable, between two positions, relative to at least one stationary end wall in which the charge inlet and the flue gas outlet are provided, and is divided into at least two compartments which communicate with each other at some distance from the flue gas outlet and are adapted to be positioned, one at a time, at respectively the charge inlet and the flue gas outlet. The heat supply means works in the compartment present at the charge inlet at just that moment, and the combustion gases from said compartment will pass the other compartment on their way towards the flue gas outlet.