PROBLEM TO BE SOLVED: To provide a firefly breeding device capable of more easily maintaining clean water quality. SOLUTION: The firefly breeding device 1 including a water tank unit 2, a firefly accommodating unit 3 for accommodating water and fireflies, a water supply unit 5, and a water discharge unit 4, and at least the firefly accommodating unit. A part of the water supply unit is located inside and above the water tank unit, and the water supply unit is filtered by a pump unit that sucks the water to be put into the water tank unit and a filtration unit 52 that filters the sucked water. A first water passage pipe 51 for allowing the water to flow into the firefly accommodating portion is provided, and the water discharge portion is provided in the firefly accommodating portion and overflows above a predetermined water surface in the firefly accommodating portion. A second water passage pipe 41 for discharging water to the water tank portion by gravity is provided, and water circulates from the water tank portion to the water tank portion via the water supply portion, the firefly accommodating portion, and the water discharge portion in this order. It is configured to be. [Selection diagram] Fig. 1【課題】より簡便に清浄な水質を維持できるホタルの飼育装置を提供する。【解決手段】水槽部２と、水及びホタルを収容するホタル収容部３と、水供給部５と、水排出部４と、を備えるホタルの飼育装置１であって、前記ホタル収容部の少なくとも一部は、前記水槽部の内部かつ上方に位置し、前記水供給部は、前記水槽部に入れられる水を吸引するポンプ部と、吸引された前記水を濾過する濾過部５２と、濾過された前記水を前記ホタル収容部の内部に流入させる第１の通水管５１と、を備え、前記水排出部は、前記ホタル収容部に設けられ、かつ、前記ホタル収容部における所定水面以上のオーバーフロー水を重力によって前記水槽部へ排出する第２の通水管４１を備え、前記水槽部から、前記水供給部、前記ホタル収容部、前記水排出部をこの順に経て、前記水槽部へ水が循環されるように構成されている。【選択図】図１
