The invention relates to an apparatus (1) for stimulating neurons having a pathological synchronous and oscillatory neural activity, said apparatus comprising a non-invasive stimulation unit (11) for applying stimuli (22) that stimulate a patient's neurons, a measurement unit (12) for recording test signals (23) that represent a neural activity of the stimulated neurons, and a control and analysis unit (10) for controlling the stimulation unit (11) and analyzing the test signals (23). The stimulation unit (11) applies first stimuli (34), and based on the test signals (23) recorded in reaction to the application of the first stimuli (34), the first stimuli (34) causing the phase of the pathological synchronous and oscillatory neural activity of the stimulated neurons to be reset are selected, whereupon the stimulation unit (11) applies the selected first stimuli (34) with a time delay, and the test signals (23) recorded in reaction to the stimuli (34, 38) applied with the time delay are used to verify whether said stimuli (34, 38) applied with the time delay suppress the pathological synchronous and oscillatory neural activity of the stimulated neurons.