The present invention provides a hot-water supply device comprising: a flow control valve for controlling the flow rate of water supplied from the outside; a heating module for heating water passed through the flow control valve and guided thereto; a hot-water discharge valve for opening or closing a channel through which the water heated by the heating module is discharged; an input unit for receiving a hot-water discharge signal; and a controller for controlling the flow control valve, the heating module, and hot-water discharge valve such that the flow rate of water supplied to the heating module is controlled step by step by the flow control valve according to signals received by the input unit.