A rotation driving device includes: a body 10, made of resin, and having an accommodation hole 13 in a cylindrical shape with an axis S as a center; a motor M, comprising a rotor 60 provided in an accommodation hole of the body and rotating around the axis and a rotation shaft 40 integrally rotating around the axis with the rotor and extending in an axial direction; a first bearing B1 fixed to an end side of the body and a second bearing B2 fixed to the other end side of the body in the axial direction, so as to rotatably support the rotation shaft; and a first cover member 110 connected to the one end side of the body and a second cover member 120 connected to the other end side of the body.