A motor drive device is disclosed having an input-side gear through which rotation of a stepping motor is transferred to a reel with a predetermined speed reduction ratio, the reel driven by the stepping motor via the input-side gear and is formed in one-piece construction with the input-side gear, and a rotary shaft support section that rotatably supports the reel. The rotary shaft support section has one end formed with a wall portion in a direction perpendicular to a longitudinal direction of the rotary shaft support section and the other end provided with a press section by which the rotatably supported reel is pressed toward the wall portion.