To suppress force of contents coming out of an outlet at the upper end of a storage bag made of a synthetic resin to prevent the contents from scattering onto a table or a floor.

The synthetic-resin-made storage bag 1 is mainly made of a synthetic resin film and has a mating section by a heat seal 3 around the periphery. A slant downward notch 4 is formed from the upper end of the bag 1 outwardly of the bag 1 at a position closer to a widthwise end from the other widthwise end at the upper end of the bag 1. The outlet for the contents is formed by slantly cutting a corner closer to one of widthwise ends of the storage bag 1 from the notch 4. A collision wall of the contents is formed of a hypotenuse 6a of a heat seal 6 formed to be approximately triangular on the upper side of the outlet on a corner closer to the widthwise end at the upper end of the storage bag 1.