Disclosed are a functional sheet including a first substrate applied or impregnated with an active ingredient, which is to be used in low temperature water at 0° C. to 30° C., wherein the active ingredient is to be physically or chemically adsorbed on a second substrate in the low temperature water, and remain on the second substrate after removal of the low temperature water, as the first substrate, a substrate having a water contact angle of 90° or less is used so that 70% or more of the active ingredient applied or impregnated to the first substrate can be released in the low temperature water at 0° C. to 30° C. within 5 minutes; and another functional sheet including a first substrate applied or impregnated with an active ingredient, which is to be used in low temperature water at 0° C. to 30° C., wherein the active ingredient is to be physically or chemically adsorbed on a second substrate in the low temperature water, and remain on the second substrate after removal of the low temperature water, the functional sheet has light transmittance of 2 to 20%, so that 70% or more of the active ingredient applied or impregnated to the first substrate can be released in the low temperature water at 0° C. to 30° C. within 5 minutes.