To provide a thin plate burring method that can increase the amount of projection of an annular portion by burring process even if a thinned plate-like workpiece is used.

The thin plate burring method includes: a first step for forming a thin portion 11C thinner than an original thickness at a target portion of a plate-like workpiece 11 by applying crushing process to the target portion; a second step for forming a circular through-hole 11D in the thin portion 11C by punching process; and a third step for forming an annular portion 11E rising from a surface of the workpiece 11 by applying projection process with burring process around the through-hole 11D formed in the thin portion 11C.