A composition for film formation includes a polymer and a solvent. The polymer includes a first repeating unit, a second repeating unit, a third repeating unit, and a structural unit on at least one end of a main chain of the polymer. The first repeating unit includes a crosslinkable group. The second repeating unit differs from the first repeating unit. The third repeating unit differs from the first repeating unit and has higher polarity than polarity of the second repeating unit. The structural unit includes an interacting group capable of interacting with Si—OH, Si—H or Si—N.