The method is for the impregnation of chips during the manufacture of chemical pulp. The chips are continuously fed without preceding steam treatment to the top of an impregnation vessel that maintains atmospheric pressure. Impregnation fluid (BL) is added to the impregnation vessel and establishes a fluid level (LIQ_LEV). The chips that have been added establish a chips level (CH_LEV) that lies at least 3-5 meters over the fluid level. The temperature at the top of the vessel essentially corresponds to ambient temperature.Impregnation fluid BL is fed in to the impregnation vessel in such an amount and at such a temperature that the temperature that is established at the fluid level (LIQ_LEV) is established within the interval 90-115° C., preferably within the interval 95-105° C.