To provide a storage bag which is handled easily from writing down information to sealing and in opening as well while the handling of a stored item and the storage bag is ensured.

In forming this storage bag, the first sheet (a front face sheet 101, an adhesive layer 102, a separation sheet 103) and the second sheet (a back face sheet 105) are closed in such a way that one direction is open and the ends in other directions are closed to be in a bag shape. The first sheet is provided with a label area 101a where information is written down and printed and which is peelable to be used. The neighborhood of the opening 100a of the first sheet is provided with a protrusive part 100b protruding more in the open direction than the second sheet. The part 100b is formed able to close the opening 100a when it is folded. An opening line 114 for facilitating the cut/open of the sealed storage bag 100 is formed on the first sheet and the second sheet.