Disclosed is an Ag-based sputtering target composed of pure Ag or Ag alloy wherein when the average grain size dave of the sputtering face of the Ag-based sputtering target is measured in accordance with the procedures 1-3 described below, the average grain size dave satisfies 10 μm or less.
(Procedure 1) In the surface of the sputtering face, a plurality of locations are optionally selected, and a micrograph (magnification: 40-2,000 times) of each selected location is taken.
(Procedure 2) Four or more straight lines are drawn in a grid pattern or radially on each micrograph, a number n of grain boundaries existing on the straight line is investigated, and a grain size d is calculated on the basis of the following equation on each straight line.
d=L/n/m - where, L represents the length of the straight line, n represents the number of the grain boundaries existing on the straight line, and m represents the magnification of the micrograph.
(Procedure 3) The average value of the grain sizes d of all selected locations is made the average grain size dave of the sputtering face.