A frothing device including a central body which is detachably associable with a steam delivery tube and an outer casing which fits over the central body. The central body forms channels for the passage of air and of liquid to be frothed, in order to mix them with the steam and consequently mix the three flows. The device further includes a first mixing region for forming a mixture composed of the air and the liquid to be frothed, which arrive respectively from an air intake channel and a liquid rising channel, which are formed by the central body and by the outer casing, the formed mixture then converges in a second mixing region with the steam that is injected in the second mixing region and arrives from the delivery tube and then enters the beverage by means of a discharge channel that extends from the second mixing region.
