A handpiece (1, 1A, 1B, 1C) with a built-in camera, comprising: (a) a handpiece body which includes a cutting tool attached to a head portion thereof, and a light receiving port provided at a position near the cutting tool; (b) a grip portion which is detachably connected to the handpiece body; and (c) a color camera module which is stored inside the handpiece body, (d) wherein the color camera module includes a camera unit having a condensing lens unit and a color image sensor that outputs a color image signal, and an arbitrary number of light-emitting elements which are circularly arranged around a periphery of the camera unit, (e) an objective lens which faces the light receiving port provided in the head portion, and (f) an optical transmission body which is disposed in the handpiece body in a state in which an incidence end thereof faces the objective lens and an exit end thereof faces the condensing lens unit; and (g) a photographing optical system which transmits imaging light of an affected area to the camera unit via the objective lens and the optical transmission body; and wherein (h) the optical transmission body is a rod fiber which is attached to the inner wall portion of the handpiece body in a state in which an incidence end thereof faces the objective lens with a predetermined interval therebetween and an exit end thereof faces the condensing lens unit with a predetermined interval therebetween; and wherein (i) wherein an interval between the objective lens and the incidence end of the rod fiber is configured to allow photographing light from the objective lens to be substantially received by a light receiving angle of the rod fiber, and an interval between the exit end of the rod fiber and the condensing lens unit is configured to allow light that exits from the rod fiber to be substantially received by the viewing angle of the condensing lens unit; and wherein (j) the light-emitting elements are arranged in a configuration in which the light-emitting elements can emit illumination light to be incident onto the rod fiber. (a) a handpiece body which includes a cutting tool attached to a head portion thereof, and a light receiving port provided at a position near the cutting tool; (b) a grip portion which is detachably connected to the handpiece body; and (c) a color camera module which is stored inside the handpiece body, (d) wherein the color camera module includes a camera unit having a condensing lens unit and a color image sensor that outputs a color image signal, and an arbitrary number of light-emitting elements which are circularly arranged around a periphery of the camera unit, (e) an objective lens which faces the light receiving port provided in the head portion, and (f) an optical transmission body which is disposed in the handpiece body in a state in which an incidence end thereof faces the objective lens and an exit end thereof faces the condensing lens unit; and (g) a photographing optical system which transmits imaging light of an affected area to the camera unit via the objective lens and the optical transmission body; and wherein (h) the optical transmission body is a rod fiber which is attached to the inner wall portion of the handpiece body in a state in which an incidence end thereof faces the objective lens with a predetermined interval therebetween and an exit end thereof faces the condensing lens unit with a predetermined interval therebetween; and wherein (i) wherein an interval between the objective lens and the incidence end of the rod fiber is configured to allow photographing light from the objective lens to be substantially received by a light receiving angle of the rod fiber, and an interval between the exit end of the rod fiber and the condensing lens unit is configured to allow light that exits from the rod fiber to be substantially received by the viewing angle of the condensing lens unit; and wherein (j) the light-emitting elements are arranged in a configuration in which the light-emitting elements can emit illumination light to be incident onto the rod fiber.