PROBLEM TO BE SOLVED: To provide a microbubble producing bathtub stably achieving efficacy such as cloudiness and skin moisture retaining effects while cutting down power consumption.SOLUTION: The microbubble producing bathtub 1 sucks hot and cold water 2 in a bathtub 3, dissolves air in hot and cold water by a gas dissolving device 11, delivers hot and cold water with the air dissolved, into the bathtub, and precipitates the air dissolved in the hot and cold water by the drop of pressure to produce microbubbles in the hot and cold water. The microbubble producing bathtub 1 includes a control part 17 controlling the operation of a pump. A steady mode corresponding to the steady operation of the pump is set to the control part, and in a steady operation mode, decrease behavior based on time of dissolved oxygen concentration in the hot and cold water is set beforehand, and the circulating amount of hot and cold water by the pump is changed based on the decrease behavior.COPYRIGHT: (C)2011,JPO&INPIT【課題】消費電力を抑えるとともに、白濁、肌の保湿効果などの効能を安定して実現することのできる微細気泡発生浴槽を提供すること。【解決手段】浴槽3内の湯水2を吸い込み、気体溶解装置11において湯水に空気を溶解させ、空気の溶解した湯水を浴槽内に送り出し、湯水に溶解した空気が圧力の低下により析出して湯水中に微細気泡を発生させる微細気泡発生浴槽1において、ポンプの動作を制御する制御部17を備え、制御部は、ポンプの定常運転に対応する定常モードが設定され、定常運転モードでは、湯水中の溶存酸素濃度の時間による減少挙動があらかじめ設定され、この減少挙動に基づいてポンプによる湯水の循環量を変化させる。【選択図】図1
