A probe pin material according to the present invention comprises an Ag-Pd-Cu-based
alloy containing Ag, Pd, Cu, Zn, Sn, and B. Regarding the concentrations of additional elements Zn, Sn, and B, the Zn concentration is 0.5-2.5
mass%, the Sn concentration is 0.5-2.5
mass%, and the B concentration is 0.05-0.5
mass%. Regarding the Ag-Pd-Cu-based
alloy according to the present invention, when X represents the Ag concentration, Y represents the Pd concentration, and Z represents Cu concentration + Zn concentration + Sn concentration + B concentration, X, Y, and Z are located within a range enclosed by straight lines connecting points A1 to A4 in an X-Y-Z pseudo
ternary phase diagram. Point A1 (X: 24 mass%, Y: 40 mass%, Z: 36 mass%) Point A2 (X: 34 mass%, Y: 40 mass%, Z: 26 mass%) Point A3 (X: 17 mass%, Y: 57 mass%, Z: 26 mass%) Point A4 (X: 7 mass%, Y: 57 mass%, Z: 36 mass%)