A moisture-absorbing sheet including a hygroscopic molded article containing a resin component and a hygroscopic agent, wherein (1) calcium oxide-based particles having a specific surface area of 0.5 m2/g to 20 m2/g and an average particle diameter of 0.5 μm to 50 μm are included as the hygroscopic agent; (2) a fibrillated fluororesin is included as the resin component; and (3) the sheet has: (a) a weight increase ratio of 1% or less after being allowed to stand for 2 hours in an atmosphere at a temperature of 20° C. and a relative humidity of 65%; and (b) a weight increase ratio of 5% or more after being allowed to further stand for 36 hours after being allowed to stand for 36 hours in an atmosphere at a temperature of 20° C. and a relative humidity of 65%.