The present invention provides a solid preparation containing compound (I) [compound (I) is as defined in the specification] or a salt thereof, and metformin hydrochloride, which is useful as a therapeutic drug for diabetes and the like, and superior in the preservation stability. A solid preparation having a first part and a second part: a first part: a part containing compound (I) or a salt thereof and substantially free of metformin hydrochloride a second part: a part containing metformin hydrochloride and substantially free of compound (I) and a salt thereof.