PURPOSE: A preparation method for monosilane is provided to increase refining efficiency by reducing the impurity concentration of hydrocarbons and ethylsilane. CONSTITUTION: A preparation method for monosilane is comprised of the steps: reacting metal hydride with silicon halide in a reaction bath; collecting monosilane and transferring unreacted material and reaction product to a neutralizing tank; inputting neutralizer to the neutralizing tank and to reduce reactivity of the unreacted material; and discharging the unreacted material with reduced reactivity.
