A wheel drive motor, comprising: a motor shaft, for outputting drive force to rotate a wheel, extending in an axial direction and including a large diameter portion located at a central part in the axial direction and a small diameter portion located on a first side in the axial direction, the small diameter portion having a diameter smaller than that of the large diameter portion, a bearing rotatably supporting the small diameter portion, and a rotor secured to an outer circumferential surface of the large diameter portion and facing a stator, wherein an end part of the rotor located on the first side in the axial direction projects over an end face of the large diameter portion located on the first side in the axial direction toward the side on which the small diameter portion is, wherein the large diameter portion has an outer diameter greater than the outer diameter of the bearing, and the end part of the rotor projects over an end part of the bearing located on a second side in the axial direction toward the side on which the small diameter portion is, and wherein the outer circumferential surface of the large diameter portion includes a large diameter portion's fitting surface that fits with a radially inner part of the rotor, and the small diameter portion has a small diameter portion's fitting surface on its outer circumference, the small diameter portion's fitting surface fitting with an inner ring member of the bearing, wherein the positions of the large diameter portion's fitting surface and the small diameter portion's fitting surface are adjacent to each other so as not to overlap with each other in the axial direction, the outer circumferential surface of the large diameter portion is a portion of the motor shaft, and wherein an end member that is fixedly attached to the large diameter portion, projects from the end face of the large diameter portion located on the first side in the axial direction, and covers an end face of the rotor located on the first side in the axial direction. a motor shaft, for outputting drive force to rotate a wheel, extending in an axial direction and including a large diameter portion located at a central part in the axial direction and a small diameter portion located on a first side in the axial direction, the small diameter portion having a diameter smaller than that of the large diameter portion, a bearing rotatably supporting the small diameter portion, and a rotor secured to an outer circumferential surface of the large diameter portion and facing a stator, wherein an end part of the rotor located on the first side in the axial direction projects over an end face of the large diameter portion located on the first side in the axial direction toward the side on which the small diameter portion is, wherein the large diameter portion has an outer diameter greater than the outer diameter of the bearing, and the end part of the rotor projects over an end part of the bearing located on a second side in the axial direction toward the side on which the small diameter portion is, and wherein the outer circumferential surface of the large diameter portion includes a large diameter portion's fitting surface that fits with a radially inner part of the rotor, and the small diameter portion has a small diameter portion's fitting surface on its outer circumference, the small diameter portion's fitting surface fitting with an inner ring member of the bearing, wherein the positions of the large diameter portion's fitting surface and the small diameter portion's fitting surface are adjacent to each other so as not to overlap with each other in the axial direction, the outer circumferential surface of the large diameter portion is a portion of the motor shaft, and wherein an end member that is fixedly attached to the large diameter portion, projects from the end face of the large diameter portion located on the first side in the axial direction, and covers an end face of the rotor located on the first side in the axial direction. an end part of the rotor located on the first side in the axial direction projects over an end face of the large diameter portion located on the first side in the axial direction toward the side on which the small diameter portion is, wherein the large diameter portion has an outer diameter greater than the outer diameter of the bearing, and the end part of the rotor projects over an end part of the bearing located on a second side in the axial direction toward the side on which the small diameter portion is, and wherein the outer circumferential surface of the large diameter portion includes a large diameter portion's fitting surface that fits with a radially inner part of the rotor, and the small diameter portion has a small diameter portion's fitting surface on its outer circumference, the small diameter portion's fitting surface fitting with an inner ring member of the bearing, wherein the positions of the large diameter portion's fitting surface and the small diameter portion's fitting surface are adjacent to each other so as not to overlap with each other in the axial direction, the outer circumferential surface of the large diameter portion is a portion of the motor shaft, and wherein an end member that is fixedly attached to the large diameter portion, projects from the end face of the large diameter portion located on the first side in the axial direction, and covers an end face of the rotor located on the first side in the axial direction.