An apparatus and a method for producing an object by means of additive manufacturing, the apparatus comprising: - a process chamber arranged for receiving in a build space of the process chamber a bath of material arranged for producing the object; - a ultrasound source element arranged for emitting a beam of focused ultrasound energy in the build space for processing a selective part of the material of the bath of material for producing the object; - a control unit, communicatively coupled to the ultrasound source element, arranged for controlling the ultrasound source element such that a frequency and/or amplitude of the beam of focused ultrasound energy is set at a predetermined frequency and/or predetermined amplitude taking into account a characteristic of material of the bath of material in a focus spot of the beam of focused ultrasound energy and/or such that a frequency and/or an amplitude of the beam of focused ultrasound energy is/are set at a predetermined value, preferably the predetermined frequency and/or the predetermined amplitude, taking into account a focus distance of the beam of focused ultrasound energy
