PURPOSE: To purify a compound with a simple method by carrying out crystallization in the vicinity of the surface of a cooling device dipped into a vessel, in which the compound is dissolved, to deposit the crystal on the cooling device, carrying the deposited crystal to a next vessel by transferring the cooling device and then, releasing the crystal from the cooling device.

CONSTITUTION: In a method for purifying a low grade compound (e.g. paradichlorobenzene) to a highly purified one by repeating crystallization, the crystal is deposited on the cooling device 13 (e.g. fin tube) by carrying out the crystallization in the vicinity of the surface of the cooling device 13 dipped into the vessel 15, in which the compound is dissolved. The deposited crystal is carried to the next vessel by transferring the cooling device 13 and then, is released from the cooling device 13. As a result, the compound is purified with a extremely simple method.