Provided is a therapeutic agent for amyotrophic lateral sclerosis, comprising: a compound represented by formula (1) (in formula (1), R1 each independently represents an alkyl group containing 1-6 carbon atoms or a 4-hydroxyphenethyl group, and n represents an integer of 1-3)； a pharmacologically acceptable salt thereof； or a solvate of the compound and the salt, as an effective ingredient.
