To provide blank material which enables improvement of the strength of a paper container l, a paper container and a paper container with lid material.SOLUTION: Blank material 30 comprises: a bottom panel 31; a plurality of side panels 33; and a plurality of flange piece panels 35. A gap 36 is formed between the side panels 33. A first recess 81 is formed on a side edge 33c of the one side panel 33. A first protrusion 82 housed in the first recess 81 is formed on a side edge 33c of the other side panel 33 which is opposed via the gap 36 to the one side panel 33. The first recess 81 is formed over the entire region of the side edge 33c of the one side panel 33. The first protrusion 82 is formed over the entire region of the side edge 33c of the other side...
