This invention provides a safe and effective agent for ameliorating chronic obstructive pulmonary disease (COPD) that has both a bronchodilator effect and an anti-inflammatory effect. The agent for ameliorating chronic obstructive pulmonary disease contains mepenzolate bromide as an active ingredient. More preferably the mode of administration of the agent for ameliorating chronic obstructive pulmonary disease is airway administration or inhalation administration, and furthermore the mode of administration thereof is oral administration or rectal administration. This invention is a safe and effective agent for ameliorating chronic obstructive pulmonary disease (COPD) that has both a bronchodilator effect and an anti-inflammatory effect of mepenzolate bromide.