The present invention provides a kneading device including a hopper having a hopper body that stores raw powder, and a mixer that kneads material to be kneaded, which contains the raw powder, wherein the hopper includes a stirring device that stirs the raw powder in the hopper body, and a temperature-controlled air supply device 6 that supplies temperature-controlled air into the hopper body. This kneading device can stably prepare high-quality kneaded dough.