on a handle 27 by means of an attachment part 1 attachment part 1 consists of an upper member 3 and a lower member 5 which are rotatable around a pin 12 when it is to be attached on a handle 27 of a bicycle attachment screw 33 is removed upper member 3 and lower member 5 are rotated around the pin 12 with its end portions expanded and attachment part 1 is attached on handle 27 of the bicycle around which a rubber 31 is wound with the attachment part 1 gripping the rubber by fastening the attachment screw 33 thereafter a force is applied to the upper and lower members 3 and 5 for gripping handle 27 and hence attachment part 1 is firmly attached on handle 27 with rubber 31 interposed at a rear portion of illuminating apparatus 29 a switching knob 35 for turning on off the lamp is provided at a lower portion of the illuminating apparatus 29 an attachment part 15 is attached by means of an attachment screw or the like at a rear portion of attachment part 15 a lever 20 used for attachment detachment to and from the attachment part 1 is provided referring to fig1 by the switching knob 35 the user can switch the lamp to a 34 high 34 state in which bright light is emitted and a 34 low 34 state in which light not so bright as in 34 high 34 state is emitted fig1 is a circuit diagram of a light emitting circuit.