PROBLEM TO BE SOLVED: To provide an Ag-oxide electric contact material improved in dispersibility of easily oxidizable metal oxide in Ag by internal oxidation, and a producing method and producing device of the Ag-oxide electric contact material.SOLUTION: A producing method of an Ag-oxide electric contact material is performed by subjecting particles comprising an alloy containing Ag and easily oxidizable metal to internal oxidation using supercritical water or subcritical water in an oxygen atmosphere. An Ag-oxide electric contact material can be obtained by the producing method. A breaker and an electromagnetic contactor include the Ag-oxide electric contact material. A producing device of an Ag-oxide electric contact material includes : a water supply source 21 which supplies water to a reactor; an oxygen gas supply source 22 for supplying oxygen gas to the reactor; and a reaction furnace 20 accommodating particles comprising an alloy containing Ag and easily oxidizable metal, receiving water and oxygen ga
