The present invention relates to an infusion unit forming a hollow inner space that receives inserted elements, characterized in that it consists of a reinforcement belt that defines the hollow inner space of the infusion unit, said belt including means for taking up the forces generated while infusing on at least one inserted element, the reinforcement belt further including receiving means for each of said elements. The invention also relates to a machine container as well as to a machine with one such infusion unit, and similarly to a method for assembling at least one element to be inserted into an infusion unit. The invention can be used in all types of infusion machines, in particular EXPRESSO coffee machines.