To provide magnetic alloy powder having a high entropy change at high efficiency.

A gas is sprayed toward a cooling disk rotating an alloy molten metal, so as to produce flat-shaped magnetic alloy powder with a thickness of 30 m. The magnetic alloy powder is heat-treated in a hydrogen-containing atmosphere, so as to obtain magnetic alloy powder for magnetic refrigeration composed of a compound phase substantially with an NaZn13 type crystal structure expressed by compositional formula of Ra(TMXM1-X)bHc (wherein, R essentially consists of La and, if required, comprises one or more kinds of rare earth elements selected from Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y and Lu; and TM essentially consists of Fe and, if required, comprises one or more kinds selected from a transition metal element group consisting of Ti, V, Cr, Mn, Co, Ni, Cu and Zn).