PURPOSE: To efficiently treat by using waste oil without complicated structure such as a screw, etc.

CONSTITUTION: The kitchen garbage incinerating furnace comprises an incinerating furnace body l having a switching cover 2 for switching a kitchen-garbage charging port 1a and a smoke exhaust cylinder 4, a waste oil supply unit having a waste oil supply hole 10 opened near a floor surface of the body 1, and an air supply unit 9 having an air supply hole 9c opened at an inner wall of the body 1. The furnace is formed by a vertical wall 8 at a ceiling between the port 1a of the body 1 and the cylinder 4 to partition the body 1 to a first combustion chamber A having the port 1 and a second combustion chamber B having the cylinder 4.