Percolating device, for example intended to equip a coffee machine, comprising a percolating chamber mounted in such a way that it can carry out a displacement in the vertical direction when a control handle is operated. A cap receiving a capsule of product to be infused is also displaced, when the handle is operated, towards the inside of the percolating chamber. A percolating head sliding freely inside the percolating chamber can occupy different relative positions inside the percolating chamber according to the size of the capsule loaded into the cap. A stop device makes it possible to lock the percolating head in a definite position in order to inject steam and/or water through the percolating head.