The present invention provides a novel pyridylaminoacetic acid compound represented by the following formula (1): (wherein R 1 , R 2 , R 3 , Y and Z are as defined in the description and claims), or a pharmacologically acceptable salt thereof. The pyridylaminoacetic acid compound has EP2 agonistic action and is therefore useful as a therapeutic and/or prophylactic agent for respiratory diseases such as asthma or chronic obstructive pulmonary disease.