A valve control system comprising: a first valve arranged in a flow path for flowing a fluid, and being openable and closable according to an electric signal; a second valve arranged in said flow path, located downstream from said first valve and being openable and closable according to an electric signal; a first sensor arranged in said flow path, and located between said first and second valves (11, 12) for detecting whether or not said fluid flows from said first valve; a second sensor arranged in said flow path, and located downstream from said second valve for detecting whether or not said fluid flows from said second valve; and a control device configured to control said first and second valves (11, 12) based on a result of detection of said first sensor and a result of detection of said second sensor, characterised in that said control device is configured: to check that the result of detection of said first sensor indicates that said fluid is not flowing from said first valve and that the result of detection of said second sensor indicates that said fluid is not flowing from said second valve, to execute first control for opening said first valve after the result of detection of said first sensor and the result of detection of said second sensor are checked, to check that the flowing of said fluid from said first valve is indicated by the result of detection of said first sensor performed after a first period elapsed since execution of said first control, to execute second control for opening said second valve in response to changing of the result of detection of said first sensor, to check that the flowing of said fluid from said second valve is indicated by the result of detection of said second sensor performed after a second period elapsed since execution of said second control, and to keep said first and second valves (11, 12) in an open state. a first valve arranged in a flow path for flowing a fluid, and being openable and closable according to an electric signal; a second valve arranged in said flow path, located downstream from said first valve and being openable and closable according to an electric signal; a first sensor arranged in said flow path, and located between said first and second valves (11, 12) for detecting whether or not said fluid flows from said first valve; a second sensor arranged in said flow path, and located downstream from said second valve for detecting whether or not said fluid flows from said second valve; and a control device configured to control said first and second valves (11, 12) based on a result of detection of said first sensor and a result of detection of said second sensor, characterised in that said control device is configured: to check that the result of detection of said first sensor indicates that said fluid is not flowing from said first valve and that the result of detection of said second sensor indicates that said fluid is not flowing from said second valve, to execute first control for opening said first valve after the result of detection of said first sensor and the result of detection of said second sensor are checked, to check that the flowing of said fluid from said first valve is indicated by the result of detection of said first sensor performed after a first period elapsed since execution of said first control, to execute second control for opening said second valve in response to changing of the result of detection of said first sensor, to check that the flowing of said fluid from said second valve is indicated by the result of detection of said second sensor performed after a second period elapsed since execution of said second control, and to keep said first and second valves (11, 12) in an open state. to check that the result of detection of said first sensor indicates that said fluid is not flowing from said first valve and that the result of detection of said second sensor indicates that said fluid is not flowing from said second valve, to execute first control for opening said first valve after the result of detection of said first sensor and the result of detection of said second sensor are checked, to check that the flowing of said fluid from said first valve is indicated by the result of detection of said first sensor performed after a first period elapsed since execution of said first control, to execute second control for opening said second valve in response to changing of the result of detection of said first sensor, to check that the flowing of said fluid from said second valve is indicated by the result of detection of said second sensor performed after a second period elapsed since execution of said second control, and to keep said first and second valves (11, 12) in an open state.