A motor with a speed reduction mechanism, comprising: a three-phase driven brushless motor, the brushless motor comprising: a stator having a motor case, formed of a magnetic material, a stator core fixed to the inner peripheral side of the motor case, and a coil wound around the stator core; and a rotor having a magnet and rotatably disposed in the stator, wherein the motor case having two parallel opposing flat surface parts (14a, 14b) opposing each other in a direction perpendicular to the axis of rotation of the rotor, and connection parts (14c, 14d, 14e, 14f) provided at both sides of the flat surface parts (14a, 14b) and connecting the flat surface parts (14a, 14b), the stator has an insulator having three coil connection terminals (26U, 26V, 26W) connected with the winding, one of the three coil connection terminals is disposed on one connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b) and the remaining two coil connection terminals (26V, 26W) are disposed on the other connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b); a frame mounted with the brushless motor and accommodating therein a speed reduction mechanism and a control circuit, the speed reduction mechanism being connected to a rotary shaft of the brushless motor, speed-reducing rotation of the rotary shaft, and outputting the speed-reduced rotation to an output shaft, the control circuit being provided for controlling drive of the brushless motor; and three intermediate terminals (43U, 43V, 43W) fitted to the frame and each having one end electrically connected to the coil connection terminal (26U, 26V, 26W) and the other end electrically connected to the control circuit, wherein the two coil connection terminals (26U, 26V, 26W) disposed on the other connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b) extend along the extending direction of the rotary shaft of the brushless motor from the end portion of the brushless motor with different lengths, and a shorter one of the two coil connection terminals (26U, 26V, 26W) having different extending lengths is disposed closer to the bottom surface side of the frame than the longer one is. a three-phase driven brushless motor, the brushless motor comprising: a stator having a motor case, formed of a magnetic material, a stator core fixed to the inner peripheral side of the motor case, and a coil wound around the stator core; and a rotor having a magnet and rotatably disposed in the stator, wherein the motor case having two parallel opposing flat surface parts (14a, 14b) opposing each other in a direction perpendicular to the axis of rotation of the rotor, and connection parts (14c, 14d, 14e, 14f) provided at both sides of the flat surface parts (14a, 14b) and connecting the flat surface parts (14a, 14b), the stator has an insulator having three coil connection terminals (26U, 26V, 26W) connected with the winding, one of the three coil connection terminals is disposed on one connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b) and the remaining two coil connection terminals (26V, 26W) are disposed on the other connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b); a stator having a motor case, formed of a magnetic material, a stator core fixed to the inner peripheral side of the motor case, and a coil wound around the stator core; and a rotor having a magnet and rotatably disposed in the stator, wherein the motor case having two parallel opposing flat surface parts (14a, 14b) opposing each other in a direction perpendicular to the axis of rotation of the rotor, and connection parts (14c, 14d, 14e, 14f) provided at both sides of the flat surface parts (14a, 14b) and connecting the flat surface parts (14a, 14b), the stator has an insulator having three coil connection terminals (26U, 26V, 26W) connected with the winding, one of the three coil connection terminals is disposed on one connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b) and the remaining two coil connection terminals (26V, 26W) are disposed on the other connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b); a frame mounted with the brushless motor and accommodating therein a speed reduction mechanism and a control circuit, the speed reduction mechanism being connected to a rotary shaft of the brushless motor, speed-reducing rotation of the rotary shaft, and outputting the speed-reduced rotation to an output shaft, the control circuit being provided for controlling drive of the brushless motor; and three intermediate terminals (43U, 43V, 43W) fitted to the frame and each having one end electrically connected to the coil connection terminal (26U, 26V, 26W) and the other end electrically connected to the control circuit, wherein the two coil connection terminals (26U, 26V, 26W) disposed on the other connection part (14c, 14d, 14e, 14f) side with respect to the flat surface parts (14a, 14b) extend along the extending direction of the rotary shaft of the brushless motor from the end portion of the brushless motor with different lengths, and a shorter one of the two coil connection terminals (26U, 26V, 26W) having different extending lengths is disposed closer to the bottom surface side of the frame than the longer one is.