To enable a whistle to be always carried around with a flashlight to prevent forgetting carrying the whistle by providing the flashlight with the whistle in such a way that it is either detachable from or integrated with the flashlight.

A light cap 4 is mounted on the front of the main body 2 of a flashlight, and a whistle 5 that serves also as a battery holding cap to hold a battery 3 is detachably mounted on the rear end of the main body. A cord for carrying around is attached to a ring 9. When the threaded part 61 of the cap portion 6 of the whistle 5 is fitted into the threaded part 21 of the main body 2, a spring 8 mounted on the cap portion 6 pushes the battery 3 forward, and an elastic O-ring 7 mounted on the cap portion 6 is pressed by the O-ring holding part 22 of the main body 2 and elastically deformed so that the whistle 5 is attached to the rear end of the main body 2.