A synchronization device for a manual transmission of a vehicle, including a synchronizer ring configured to synchronize rotation of a transmission gear and clutch hub. The synchronizer ring includes: a ring body having an annular shape; an axial protruding portion protruding from the ring body toward the clutch hub in an axial direction to set a size of an axial clearance between the ring body and the clutch hub; and a radial protruding portion protruding from the ring body toward the clutch hub in a radial direction intersecting the axial direction to set a size of a radial clearance to be formed between the ring body and the clutch hub. The ring body, the axial protruding portion, and the radial protruding portion are formed integrally by metal stamping.