This article discusses the measurement of hydrogen storage capacity in Ca72Mg28 alloy that has been produced by melt spinning. The alloy has an amorphous structure in which there is an assumption of hydrogen storage of acceptable concentration. The research is to analyse the possibility of desorption of the gas without recrystallization of the alloy. Subsequently, the problem of reversible hydrogen storage is examined at temperatures between 410-450 ° C in the pressure range 0 to 3.5 MPa. This paper deals with the indirect determination of the amount of heat generated in the absorption of hydrogen by using the calorimetric method. In the conclusion there is a comparison of the storage capacity of hydrogen in the amorphous and crystalline structure of the alloy.