To provide a gear with an improved strength that hardly generates a noise.

A gear (1) is configured to cover, with a covered section (20) made of a predetermined resin, metal tooth sections in a metal boss (10) with a generally gear shape having a plurality of the metal tooth sections (12) radially protruding from a periphery of a boss section (11) having a predetermined axial center. The radius (r2) of an addendum circle of the metal boss is larger than the radius (r3) of a dedendum circle of the gear. The metal tooth sections of the metal boss reinforce tooth dedendum of the tooth sections (2) of the gear.