Abstract: An object of the present invention is to provide an incubator with improved control performance for the temperature and humidity in an inner box. The present invention is an incubator comprising an outer box having an inner portion made from a heat insulating material, an inner box disposed in the outer box through a space defined between the inner portion of the outer box and the inner box, a heating unit disposed in the space and adapted for heating the inside of the inner box, the heating unit being constructed of a plurality of heating means disposed at least on a bottom wall and left and right side walls of the inner box, and a control unit for independently controlling each of the heating means.