A liquid absorbing sheet includes a liquid absorbing resin layer that can effectively absorb nonaqueous electrolyte solutions 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 UV-rays onto a monomer composition to polymerize the monomer composition, the monomer composition containing: a monofunctional monomer component containing a monofunctional monomer capable of forming a homopolymer that is soluble in a nonaqueous solvent used in a nonaqueous electrolyte secondary battery; and a polyfunctional monomer component.