The present invention relates to a stable pharmaceutical composition of a compound represented by formula (I) (chemical formula 1) or a pharmaceutically acceptable salt thereof, or a solvate of the same. A stable pharmaceutical composition of the compound represented by formula (I) or a pharmaceutically acceptable salt thereof, or a solvate of the same, can be produced by including: 1) a compound represented by formula (I) or pharmaceutically acceptable salt thereof, or a solvate of the same; 2) one or more selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides, transition metal chlorides, and magnesium chloride; and 3) sugar and/or a sugar alcohol.