PROBLEM TO BE SOLVED: To provide slightly acidic hypochlorous acid water containing fine bubble excellent thermal stability and a method for producing the same, and the slightly acidic hypochlorous acid water causing bacteria elimination and sterilizing effect remaining in the surface of living bodies and exhibiting excellent effect for sterilizing sealed space by holding effective chlorine concentration.SOLUTION: Aqueous solution containing hypochlorous acid into which carbon dioxide gas is dissolved contains fine bubbles of a particle size of 50 μm or less by a microbubble generating device B as the aqueous solution containing hypochlorous acid into which carbon dioxide gas is dissolved.