One object of the present disclosure is to provide a production method of magnesium hydride that is free of carbon dioxide and has high production efficiency, a power generation system that does not emit carbon dioxide or radiation using magnesium hydride, and an apparatus for producing magnesium hydride; therefore, the method for producing magnesium hydride of the present disclosure comprises a procedure for irradiating a magnesium compound different from magnesium hydride with hydrogen plasma, and a procedure for depositing a magnesium product containing magnesium hydride on a depositor for depositing magnesium hydride disposed within the range in which hydrogen plasma is present, wherein the surface temperature of the depositor is kept no more than a predetermined temperature at which magnesium hydride precipitates.