To provide a classification device in which product fine powder little in mixture ratio of coarse particles can be obtained. A classification device characterized in that a setting pitch P between stationary fins 13 and a width L of each stationary fin 13 are combined so that a value of P/L is in a range between 0.042×(θ−50)+0.64 and 0.019×(θ−50)+0.22 in 50°≦θ≦70° when θ is an inclination angle of each stationary fin 13, P is the setting pitch, and L is the width in a direction of circulation of particles.