An automatic extraction device comprising: a displacement measuring unit configured to transmit a measurement signal to measure a distance to a container (c) and generate a measurement value (sig_d) corresponding to the distance to the container; a control unit configured to output a water extraction signal (sig_dis); and a water extraction cock configured to open a water extraction valve to supply fluid to the container (c) when the water extraction signal (sig_dis) is input, characterized in that the control unit is configured to when the measurement value (sig_d) is within a preset target distance range and not changed for a preset reference period of time, output the water extraction signal (sig_dis) to control the water extraction cock to extract water for a preset target water extraction period of time or by a preset target water extraction flow rate and count a water extraction period of time during which fluid is extracted from the water extraction cock or a water extraction flow rate as an accumulated flow rate at which fluid is extracted, after the water extraction signal (sig_d) is output, outputting a water extraction stop signal in such a manner that the fluid supply from the water extraction cock is stopped and stopping counting the water extraction period of time or the water extraction flow rate when the measurement value (sig_d) is within a preset target distance range and is increased by more than a preset variation, and after the water extraction stop signal is output, outputting a water extraction resumption signal for resuming water extraction from the water extraction cock and counting the stopped water extraction period of time and the water extraction flow rate when the measurement value (sig_d) is not changed for a preset waiting period of time. a displacement measuring unit configured to transmit a measurement signal to measure a distance to a container (c) and generate a measurement value (sig_d) corresponding to the distance to the container; a control unit configured to output a water extraction signal (sig_dis); and a water extraction cock configured to open a water extraction valve to supply fluid to the container (c) when the water extraction signal (sig_dis) is input, characterized in that the control unit is configured to when the measurement value (sig_d) is within a preset target distance range and not changed for a preset reference period of time, output the water extraction signal (sig_dis) to control the water extraction cock to extract water for a preset target water extraction period of time or by a preset target water extraction flow rate and count a water extraction period of time during which fluid is extracted from the water extraction cock or a water extraction flow rate as an accumulated flow rate at which fluid is extracted, after the water extraction signal (sig_d) is output, outputting a water extraction stop signal in such a manner that the fluid supply from the water extraction cock is stopped and stopping counting the water extraction period of time or the water extraction flow rate when the measurement value (sig_d) is within a preset target distance range and is increased by more than a preset variation, and after the water extraction stop signal is output, outputting a water extraction resumption signal for resuming water extraction from the water extraction cock and counting the stopped water extraction period of time and the water extraction flow rate when the measurement value (sig_d) is not changed for a preset waiting period of time.