The invention presents a therapeutic agent (and progress suppressant) for amyotrophic lateral sclerosis (ALS) containing HGF and/or HGF gene as active ingredient. HGF has an effect of improving the motor function of ALS and life span through two actions, that is, direct neuronutrient factor activity on motoneurons, and indirect improving action of glutamate cytotoxicity on motoneurons by maintaining the level of glutamate transporter in astrocytes. Hence, HGF and/or HGF gene can be used as an effective therapeutic agent not known in the past.
