A cutting tool of a cutting machine having a base part and a bit holder. According to this invention, the bit holder has a plug-in attachment, retained in a socket of the base part that has a stop against which the bit holder rests. To prevent the penetration of water and stone dust and to allow the bit holder to be easily detached from the base part, a sealing element is located between the bit holder and the base part, surrounding at least sections of the socket.