Provided is a fiber reinforced resin gear whose durability in use under a high temperature is enhanced. A fiber reinforced resin gear is formed by injecting a resin material containing glass wool into the inside of a cavity of a mold. A fiber diameter of the glass wool is scattered in a wide range of 0.1 to 15 μm, and is distributed such that a most frequent value of the fiber diameter appears within a range of 2 to 5 μm, and an average fiber diameter of the glass wool falls within a range of 3 to 5 μm. The fiber reinforced resin gear according to the present invention can enhance durability and abrasion resistance under a high temperature compared to a conventional fiber reinforced resin gear.