To provide a film unit, in which a trapping space for an excess developing liquid is maintained without increasing the size of a trapping region.

A mask sheet 12 and a trapping material 14 are bonded with an adhesive 15 linearly applied on the edge side of the mask sheet 12 from the center of the minor sides of the trapping material 14 and along the edge of the major side of the trapping material 14. For the trapping material 14, a nonwoven fabric having 70% or higher porosity is used, and the surface of the nonwoven fabric impregnated with a larger amt. of acid polymers is used as the adhering face.