To provide a crystallization device with a simple structure and high classification performance in crystallization at a center part of an upper part in a vertical container having a classification leg on a bottom portion, rotor blade unit for generating a swirling flow of a raw material liquid of a suspension slurry in the container along an inner circumferential surface of the container is provided, and at a center part on a bottom surface of the container, liquid-flow direction changing unit for causing the raw material liquid to flow upward at the center part of the container is provided, and the liquid-flow direction changing unit is formed of baffles, each being made of a band-shaped plate, provided radially on the bottom surface.