PROBLEM TO BE SOLVED: To provide a functional gas-dissolved hot water supply device which can be easily installed even in a narrow place without requiring a large arrangement space in the horizontal direction. SOLUTION: The carbonated hot water supply device which is an example of the functional gas melting hot water supply device of the present invention includes heat exchangers 3, 5, heating means 7, 9, internal hot water supply pipe 13, carbon dioxide gas dissolving device 15, and carbon dioxide gas. The supply pipe 17 is provided in the housing 1. The carbon dioxide gas cylinder has a cylinder main body that stores carbon dioxide gas inside, and an engaging portion that protrudes from the cylinder main body and can discharge carbon dioxide gas by engagement. The bottom wall of the housing 1 is provided with an engaged portion 17a that is connected to the carbon dioxide gas supply pipe 17 and is engaged with the engaging portion. [Selection diagram] Fig. 1【課題】水平方向に大きな配設スペースを要することなく、狭小地にも設置し易い機能性ガス溶解温水供給装置を提供する。【解決手段】本発明の機能性ガス溶解温水供給装置の一例である炭酸温水供給装置は、熱交換器３、５、加熱手段７、９、内部給湯管１３、炭酸ガス溶解装置１５及び炭酸ガス供給管１７が筐体１内に設けられている。炭酸ガスボンベは、炭酸ガスを内部に貯留するボンベ本体と、ボンベ本体から突出し、係合によって炭酸ガスを吐出可能な係合部とを有している。筐体１の底壁には、炭酸ガス供給管１７と接続され、係合部が係合される被係合部１７ａが設けられている。【選択図】図１
