An apparatus and method of high pressure treatment of bulk material by extraction and/or impregnation may involve treating bulk material in an internal volume of a pressure vessel apparatus at a high pressure level in a range from 40 to 1000 bar under isolation from the environment. The high pressure treatment may be performed charge-wise in a closed system in the pressure vessel apparatus in that the bulk material is supplied charge-wise to the internal volume with the pressure vessel apparatus closed and is positioned in at least one treatment plane. Upon completion of the high pressure treatment, the bulk material is discharged charge-wise from the internal volume with the pressure vessel apparatus closed. This also gives advantages in terms of handling, especially also with regard to material flow, and with regard to operational reliability.