A column oven that may enable a heat block to provide the best temperature distribution, and increase temperature evenness of a column is provided. In a column oven 400 that heats or cools a heat block 10 contacting a column 40 and adjusts temperature of the column 40 through heat transmission from the heat block 10, a plurality of temperature adjustment bodies 21 and 22 is separately disposed along the longitudinal direction of the heat block 10, and heats or cools the heat block 10, a plurality of temperature sensors 31 and 32 measuring the temperatures of the heat block 10 adjacent to the temperature adjustment bodies 21 and 22 is also disposed, and the corresponding temperature adjustment bodies 21 and 22 are controlled independently according to the temperatures measured by the temperature sensors 31 and 32.