A liquid absorbing sheet has a liquid-absorbing resin layer that can effectively absorb the nonaqueous electrolyte solution used in nonaqueous electrolyte secondary cells that make nonaqueous electrolyte battery packs (in particular, lithium ion-based nonaqueous secondary battery packs). The liquid-absorbing resin layer is obtained by irradiating a particular monomer composition with UV rays or other energy rays to polymerize the monomer composition. The monomer composition contains a monofunctional monomer component (A) having a polyethylene glycol acrylate monomer and an amide bond-containing acrylic monomer; and a polyfunctional monomer component (B).