Provided is a method for producing roasted nori, comprising a heating treatment step in which immobilized sheet-like nori is treated with superheated steam for at least one second. The present invention also relates to a heating treatment machine for heat-treating sheet-like nori, which includes: a nori placement section that has an upper surface on which nori is placed, and a lower surface located at the side opposite to the upper surface； an uplift prevention section which has a lower surface disposed so as to face the upper surface of the nori placement section, and which is configured to be situated so as to leave a space of at most 50 mm between the upper surface of the nori placement section and the lower surface of the uplift prevention section； a superheated steam blast port for blasting superheated steam over the nori placed on the nori placement section； and a superheated steam generation device for generating superheated steam and supplying the superheated steam to the superheated steam blast port.
