Device and method suitable for disinfecting herbs in small quantities, e.g. for home use, using plasma, are disclosed. The device comprises a sealable vessel dimensioned and configured to contain herbs in chunks, in granular form such as particles or in powder, in a treatment region of the sealable vessel. The device further comprises a power source configured to generate electromagnetic (EM) power sufficient for plasma generation in a plasma generation region of the sealable vessel. The sealable vessel is optionally detachable from the device. A portable sealable vessel configured to store and transport herbs, the herbs being microbially sealed therein, is also disclosed. The portable sealable vessel may be positioned in a slot of the device so as to generate plasma in the portable sealable vessel and disinfect the herbs. A multi-slot device is also disclosed, enabling plasma disinfection of herbs in a multitude of distinct sealable vessels.