The invention proposes a device for preparing a beverage from a food substance contained in a capsule by injection of a liquid into the capsule provided to the device, said device comprising an extraction head (20) having an aperture (22) for inserting a capsule (24) into a receiving chamber (25) of the device, a closing mechanism (21) to selectively enclose said capsule by a relative movement of at least two enclosing members (10, 25b), and at least one injection member (1) comprising a support member (2) and at least one injection element (3), for receiving a liquid, attached to said support member (2) which is arranged to inject liquid into a capsule (24) provided to the device, wherein the injection member (1) is releasably mounted on a support (10) at the injection side of said receiving chamber (25) by means of a releasable connection mechanism (4a, 4b, 12).