The invention relates to an extracorporeal blood treatment machine, such as a dialysis machine, comprising leakage detection as well as to a method of detecting leakages in the dialysis fluid circuit of a dialysis machine, wherein at least part of the dialysis fluid system to be monitored in terms of leakage is accommodated in a hermetically sealed housing and the housing is or can be ventilated in a controlled manner, and wherein a parameter, such as the air humidity of the air flowing into the housing is compared to a corresponding parameter, preferably air humidity of the air flowing out of the housing.
