A valve control apparatus for driving a valve for controlling the flow rate of a fluid flowing through a fluid channel , comprising: a pulse motor for coupling to said valve ; and a motor control unit for controlling the pulse motor ; wherein the motor control unit comprises: a motor control section for applying drive pulses to the pulse motor ; the valve control apparatus being characterised in that it comprises: a counting section for counting the number of drive pulses applied to the pulse motor by the motor control section ; a voltage-drop detecting section for detecting a voltage drop of a drive power supply for the motor control section ; and a writing section for writing a count from the counting section in a nonvolatile memory if the voltage-drop detecting section detects the voltage drop, and wherein the motor control section is configured to execute return-to-origin control for returning said valve in use to an origin at the start of driving of the pulse motor by reading the count written in the nonvolatile memory and driving the pulse motor based on the count and wherein the motor control section is configured to apply drive pulses corresponding to a target open/close value of said valve to the pulse motor after execution of the return-to-origin control. a pulse motor for coupling to said valve ; and a motor control unit for controlling the pulse motor ; wherein the motor control unit comprises: a motor control section for applying drive pulses to the pulse motor ; the valve control apparatus being characterised in that it comprises: a counting section for counting the number of drive pulses applied to the pulse motor by the motor control section ; a voltage-drop detecting section for detecting a voltage drop of a drive power supply for the motor control section ; and a writing section for writing a count from the counting section in a nonvolatile memory if the voltage-drop detecting section detects the voltage drop, and wherein the motor control section is configured to execute return-to-origin control for returning said valve in use to an origin at the start of driving of the pulse motor by reading the count written in the nonvolatile memory and driving the pulse motor based on the count and wherein the motor control section is configured to apply drive pulses corresponding to a target open/close value of said valve to the pulse motor after execution of the return-to-origin control. a counting section for counting the number of drive pulses applied to the pulse motor by the motor control section ; a voltage-drop detecting section for detecting a voltage drop of a drive power supply for the motor control section ; and a writing section for writing a count from the counting section in a nonvolatile memory if the voltage-drop detecting section detects the voltage drop, and wherein the motor control section is configured to execute return-to-origin control for returning said valve in use to an origin at the start of driving of the pulse motor by reading the count written in the nonvolatile memory and driving the pulse motor based on the count and wherein the motor control section is configured to apply drive pulses corresponding to a target open/close value of said valve to the pulse motor after execution of the return-to-origin control. <EOS>