A receptacle holding unit (1) for a device for preparing a beverage from an ingredient contained in a receptacle (2) having: —a first part (10); —a second part (20) that is movable towards the first part, in particular along a longitudinal axis (1′), into a closed position for holding the receptacle in such unit and relatively apart from the first part into an open position for inserting the receptacle into such unit and/or for removal therefrom; —a fastening device (11, 21) having a fastened configuration for fastening together the first and second parts (10, 20) in the closed position and an unfastened configuration such to enable movement of the first and second parts out of the closed configuration; and —an actuator (30) movable between an open configuration and a closed configuration to drive the first part and the second part between the open and the closed positions. The actuator is movable along a straight axis (1′) to drive the first part (10) and the second part (20) into the closed position and further movable along said axis (1′) to actuate the fastening device (11, 21) from the unfastened configuration to the fastened configuration.