An Ag-Cu-WC contact forming material for a vacuum interrupter comprising a highly conductive component comprising Ag and Cu and an arc-proof component comprising WC wherein the content of the highly conductive component is such that the total amount of Ag and Cu(Ag+Cu) is from 25% to 65% by weight and the percentage of Ag based on the total amount of Ag and Cu[Ag/(Ag+Cu)] is from 40% to 80% by weight; wherein the content of the arc-proof component is from 35% to 75% by weight; wherein the structure of the contact forming material comprises a matrix and a discontinuous phase of the highly conductive component, the discontinuous phase having a thickness or width of no more than 5 micrometers, and a discontinuous grain of the arc-proof component having a grain size of no more than 1 micrometer; and wherein the discontinuous phase of the highly conductive component is finely and uniformly dispersed in the matrix at intervals of no more than 5 micrometers.
