Disclosed is a solid preparation which comprises at least one active ingredient and at least one dissolution-controlling base substance and can be formed by compression molding, wherein the dissolution-controlling base substance contains 5.0 to 99.9% by weight (inclusive) of a modified starch having a moisture retaining capacity of 400% or more and a gel indentation load of 200 g or more, containing a water-soluble ingredient in an amount of 40 to 95% by weight, having particles passing through a 75 μm-mesh sieve in the proportion of 90% by weight or more and particles passing through a 32 μm-mesh sieve in the proportion of 20% by weight or more, and having an average particle diameter of not smaller than 20 μm and smaller than 50 μm.