THERE ARE PROVIDED A WARM WATER SUPPLY DEVICE AND A WARM WATER SUPPLY METHOD, AND MORE PARTICULARLY, AN INSTANT WARM WATER SUPPLY DEVICE AND AN INSTANT WARM WATER SUPPLY METHOD CAPABLE OF SUPPLYING WARM WATER WITHIN A SHORT TIME BY CONTROLLING A FLOW RATE. THE WARM WATER SUPPLY DEVICE INCLUDES: A HEATER HEATING WATER INTRODUCED THEREIN WITH A HEATING CAPACITY AN INTRODUCTION VALVE ADJUSTING AN AMOUNT OF WATER INTRODUCED TO THE HEATER AND A VALVE CONTROLLER CONTROLLING A DEGREE OF OPENING AND CLOSING OF THE INTRODUCTION VALVE BY USING A TARGET WATER TEMPERATURE AND THE HEATING CAPACITY. FIGURE 2
