The present disclosure relates to a novel integrate-and-fire (IF) neuron circuit using a single-gated feedback field-effect transistor (FBFET) to realize small size and low power consumption. According to the present disclosure, the neuron circuit according to one embodiment may generate potential by charging current input from synapses through a capacitor. In this case, when the generated potential exceeds a threshold value, the neuron circuit may generate and output a spike voltage corresponding to the generated potential using a single-gated feedback field-effect transistor connected to the capacitor. Then, the neuron circuit may reset the generated spike voltage using transistors connected to the feedback field-effect transistor.