Planetary gear reduction mechanism

A planetary gear reduction mechanism having a plurality of gears, comprising:

• an input side rotating body connected to a drive source so as to be capable of transmitting power;
• a sun gear provided on the input side rotating body;
• an internal gear disposed on a radially outer side of the sun gear;
• a planetary gear disposed between the sun gear and the internal gear;
• a planetary carrier rotatably supporting the planetary gear;
• and
• an output side rotating body fixed to the planetary carrier and driving an object to be driven,
• wherein the planetary carrier comprises a support shaft fixing hole to which a support shaft that rotatably supports the planetary gear is fixed, and
• the output side rotating body is fixed to the planetary carrier by a fixing member fixed to the support shaft fixing hole, wherein the fixing member is press-fitted into the support shaft fixing hole provided in the planetary carrier.