A method for producing a starch-containing solid composition for heat-cooking utilizes an extruder that contains a screw that is turned by a motor; a barrel that surrounds the outer periphery of the screw; a feeder that is attached to the base side of the barrel and that is for loading a food material; and a die part that is attached to the tip side of the barrel and that is for discharging the food material after kneading while shaping the food material. The screw has, in order from the base side to the tip side, at least a flight section and a kneading section. The length of the flight section is not less than 50% of the entire length of the screw. The length of the kneading section is less than 50% of the entire length of the screw.