A stable liquid pharmaceutical formulation comprising: an anti-influenza virus antibody or a mixture of two or more different anti-influenza virus antibodies; a surfactant selected from polysorbate, poloxamer, or a mixture thereof; a sugar or its derivative selected from sorbitol, mannitol, trehalose, sucrose, or a mixture of two or more thereof; and an amino acid selected from aspartic acid, histidine, lysine, arginine, or a salt thereof; wherein the anti-influenza virus antibody comprises any one antibody selected from the group consisting of: i) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 1, a CDR2 region of SEQ ID NO: 2 and a CDR3 region of SEQ ID NO: 3, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 4, a CDR2 region of SEQ ID NO: 5 and a CDR3 region of SEQ ID NO: 6; ii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 7, a CDR2 region of SEQ ID NO: 8 and a CDR3 region of SEQ ID NO: 9, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 10, a CDR2 region of SEQ ID NO: 11 and a CDR3 region of SEQ ID NO: 12; iii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 13, a CDR2 region of SEQ ID NO: 14 and a CDR3 region of SEQ ID NO: 15, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 16, a CDR2 region of SEQ ID NO: 17 and a CDR3 region of SEQ ID NO: 18; iv) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 19, a CDR2 region of SEQ ID NO: 20 and a CDR3 region of SEQ ID NO: 21, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 22, a CDR2 region of SEQ ID NO: 23 and a CDR3 region of SEQ ID NO: 24; v) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 25, a CDR2 region of SEQ ID NO: 26 and a CDR3 region of SEQ ID NO: 27, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 28, a CDR2 region of SEQ ID NO: 29 and a CDR3 region of SEQ ID NO: 30; vi) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 31, a CDR2 region of SEQ ID NO: 32 and a CDR3 region of SEQ ID NO: 33, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 34, a CDR2 region of SEQ ID NO: 35 and a CDR3 region of SEQ ID NO: 36; and vii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 37, a CDR2 region of SEQ ID NO: 38 and a CDR3 region of SEQ ID NO: 39, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 40, a CDR2 region of SEQ ID NO: 41 and a CDR3 region of SEQ ID NO: 42. an anti-influenza virus antibody or a mixture of two or more different anti-influenza virus antibodies; a surfactant selected from polysorbate, poloxamer, or a mixture thereof; a sugar or its derivative selected from sorbitol, mannitol, trehalose, sucrose, or a mixture of two or more thereof; and an amino acid selected from aspartic acid, histidine, lysine, arginine, or a salt thereof; i) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 1, a CDR2 region of SEQ ID NO: 2 and a CDR3 region of SEQ ID NO: 3, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 4, a CDR2 region of SEQ ID NO: 5 and a CDR3 region of SEQ ID NO: 6; ii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 7, a CDR2 region of SEQ ID NO: 8 and a CDR3 region of SEQ ID NO: 9, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 10, a CDR2 region of SEQ ID NO: 11 and a CDR3 region of SEQ ID NO: 12; iii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 13, a CDR2 region of SEQ ID NO: 14 and a CDR3 region of SEQ ID NO: 15, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 16, a CDR2 region of SEQ ID NO: 17 and a CDR3 region of SEQ ID NO: 18; iv) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 19, a CDR2 region of SEQ ID NO: 20 and a CDR3 region of SEQ ID NO: 21, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 22, a CDR2 region of SEQ ID NO: 23 and a CDR3 region of SEQ ID NO: 24; v) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 25, a CDR2 region of SEQ ID NO: 26 and a CDR3 region of SEQ ID NO: 27, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 28, a CDR2 region of SEQ ID NO: 29 and a CDR3 region of SEQ ID NO: 30; vi) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 31, a CDR2 region of SEQ ID NO: 32 and a CDR3 region of SEQ ID NO: 33, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 34, a CDR2 region of SEQ ID NO: 35 and a CDR3 region of SEQ ID NO: 36; and vii) an antibody comprising a light-chain variable region comprising a CDR1 region of SEQ ID NO: 37, a CDR2 region of SEQ ID NO: 38 and a CDR3 region of SEQ ID NO: 39, and a heavy-chain variable region comprising a CDR1 region of SEQ ID NO: 40, a CDR2 region of SEQ ID NO: 41 and a CDR3 region of SEQ ID NO: 42.